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Introduction

Very few displays reach the status of being legendary in the market, but the Asus ROG Swift PG278Q has been so popular since its release in July 2014 that it is simply known by many now as the "ROG Swift". It's still one of the best gaming screens on the market today and offered the kind of performance features which serious gamers have been looking for since it was first announced. It hasn't been for everyone though, as some people just can't live with some of the limitations of the TN Film panel technology that was used in that screen - mainly the restrictive viewing angles and colour/gamma shift. It's firmly a gaming screen of course, but for other uses it couldn't compete with the wide range of popular IPS and VA panels on the market. Other screens released over the last year like the Acer Predator XB270HU and Asus's own MG279Q have combined high quality gaming performance and features with the benefits of the more rounded IPS-type technology. As a result, the popularity of the original ROG Swift has declined, and more people have moved to these new, more well-rounded offerings.

Asus have now released the new PG279Q to combat this trend. It's very similar overall in appearance, features and specs to the old PG278Q but with one key change. This new model uses an IPS-type panel and so offers a better and more rounded performance than the older model. "ROG Swift" is just a brand of course, so we can't really refer to the old PG278Q simply as the ROG Swift any more, especially now with this new model available. We will have to refer to them as the PG278Q and PG279Q, or perhaps if you like, as the "ROG Swift TN" and "ROG Swift IPS". Asus have stuck with important aspects of the old display here like the 2560 x 1440 resolution, fast response time (now quoted at 4ms G2G), 144Hz refresh rate (more if you overclock it), G-sync support, ULMB support and the style and build quality of their ROG products. We will test how this new model compares with its predecessor and how the move to an IPS-type panel has changed its performance, for the good or bad.

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Specifications and Features

The following table gives detailed information about the specs of the screen:

The PG279Q offers a limited range of connectivity options given the use of a G-sync module. However, these have improved since the early G-sync capable screens including the PG278Q which only featured a single DisplayPort interface. This model offers DP 1.2a and an additional HDMI 1.4 input as well which is useful. The digital interfaces are HDCP certified for encrypted content and the video cables are provided in the box for DisplayPort and HDMI, along with a USB cable.

Above: Asus ROG Swift PG279Q boxed up

The screen has an external power supply brick which comes packaged along with the power cable you need. There are also 2x USB 3.0 ports, located on the back of the screen next to the video and power connections. There are also some 2x 2W integrated speakers, but no further extras like card readers, ambient light sensors or human motion sensors provided as those are more aimed at office uses, while this is primarily a gaming screen.

Below is a summary of the features and connections of the screen:

OSD Menu

   
Above: OSD control buttons on the back of the screen. Click for larger version

Pressing any of the buttons (except pressing the joystick in) brings up the above quick launch menu in the bottom right hand corner, next to where the corresponding buttons would be on the back. From this menu there is quick access to the GamePlus menu (third icon down) and Turbo mode (bottom icon).

The GamePlus quick access menu is shown above, with options for the cross-hair, timer and FPS counter. The Turbo button allows you to quickly cycle between refresh rates of 60, 120Hz and 144Hz (or whatever you've set your overclocked refresh rate to if using that feature).

Pressing the joystick in brings up the main menu as shown above. It is split in to 7 sections down the left hand side, with the options available in each shown on the right. We did feel the order of these sections was perhaps a little odd, with some of the more commonly needed options (like brightness, RGB etc) a few sections down.

The first section was simply for the overclocking feature. When enabled, you could then select your maximum overclocked refresh rate from a slider. We will look at that in more detail later on including what you need to use this feature.

The second section allows you to change the preset modes as shown above. You can customise and save a setup for each mode which was handy.

The third section allows you to turn on the blue light filter if you want, for reduced blue spectral output form the W-LED backlight. May be handy to those sensitive to blue light or looking for eye care benefits.

The fourth menu has useful settings for brightness, contrast and colour temp mode. There is a user mode available here which allows you to calibrate the RGB levels manually.

The 'image' menu has a couple of useful features. There is the OD setting for controlling the response time, and then (greyed out here so a little hard to see), the ULMB (Ultra Low Motion Blur) option.

The 'input select' allow you to switch between DP and HDMI input if you are connecting multiple devices. Sadly there's no quick access control to switch between the two inputs which would have been handy for those connecting more than one device.

Finally the 'system setup' section allows you to control a few settings, mostly related to the menu itself. Although you can control the sound here (for integrated speakers / headphone connection) and the "light in motion" glow from the stand. A little tip: if you turn off the DisplayPort deep sleep option in this section the screen turns off and on instantly from a touch of the power button.

All in all the menu was very responsive and easy to navigate thanks to the joystick control. It felt intuitive to move around and there were quite a lot of options to play with. we would have perhaps liked to have seen a different order to the sub-menus and the ability to choose what the quick launch access gave you.

Power Consumption

In terms of power consumption the manufacturer lists a power on usage of <90.0W, and 0.5W in standby. We carried out our normal tests to establish its power consumption ourselves.

We tested this ourselves and found that out of the box the screen used 39.6W at the default 80% brightness setting. Once calibrated the screen reached 26.9W consumption, and in standby it used only 1.3W. We have plotted these results below compared with other screens we have tested. The calibrated consumption is very similar to the PG278Q model, and competing offerings like the Acer XB270HU and Asus MG279Q.

Panel and Backlighting

Panel Part and Colour Depth

The Asus ROG Swift PG279Q features an AU Optronics M270Q008 V0 AHVA (IPS-type) panel which is capable of producing 16.7 million colours with a true 8-bit colour depth. This is a new panel that we've not seen in any screen before. Early reports and some other reviews have wrongly stated that the screen is using the same M270DAN02.3 panel as the similarly spec'd Acer XB270HU and Asus MG279Q. That isn't right though, and isn't really logical given that this is a new borderless / frameless style panel as well. We expect to see this new panel used in the forthcoming Acer XB271HU when that's released too.

We want to try and ensure there's no confusion between AHVA and IPS as well at this juncture. AHVA (Advanced Hyper Viewing Angle) is a relatively new technology developed by AU Optronics, not to be confused with their more long-standing technology AMVA (Advanced Multi-Domain Vertical Alignment). It is AU Optronics' answer to LG.Display's very popular, and long-established IPS (In Plane Switching) technology. Testing of this technology has revealed that it is for all intents and purposes the same as IPS. Performance characteristics, features and specs are all pretty much identical. AUO weren't allowed to simply call their technology IPS due to trademark issues, which is why they adopted their own new name. Samsung are the same with their PLS (Plane to Line Switching) panel tech, which is another IPS-clone. You will see pretty much all monitor manufacturers now simply use the term IPS, since it is so well known in the market, but underneath they may be using an IPS version from LG.Display, AU Optronics or Samsung potentially. People should not get concerned with the semantics here, which is why we will continually refer to this as an "IPS-type" panel throughout the review.

The part is confirmed when dismantling the screen.

Screen Coating

The screen coating on the PG279Q is a light anti-glare (AG) offering, the same as that featured on other modern AHVA panels as well, including the Acer XB270HU and Asus MG279Q. It isn't a semi-glossy coating, but it is light as seen on other modern IPS type panels. Thankfully it isn't a heavily grainy coating like some old IPS panels feature and is also lighter than modern TN Film panel coating, including popular gaming screens and the old PG278Q model. It retains its anti-glare properties to avoid too many unwanted reflections of a full glossy coating, but does not produce an too grainy or dirty an image that some thicker AG coatings can. There were some very slight cross-hatching patterns visible on the coating if you looked very closely, but nothing very obvious.

Backlight Type and Colour Gamut

The screen uses a White-LED (W-LED) backlight unit which has become very popular in today's market. This helps reduce power consumption compared with older CCFL backlight units and brings about some environmental benefits as well. The W-LED unit offers a standard colour gamut which is approximately equal to the sRGB colour space. Anyone wanting to work with wider colour spaces would need to consider wide gamut CCFL screens or the newer range of GB-r-LED type displays available now. If you want to read more about colour spaces and gamut then please have a read of our detailed article.

Backlight Dimming and Flicker

We tested the screen to establish the methods used to control backlight dimming. Our in depth article talks in more details about a common method used for this which is called Pulse Width Modulation (PWM). This in itself gives cause for concern to some users who have experienced eye strain, headaches and other symptoms as a result of the flickering backlight caused by this technology. We use a photosensor + oscilloscope system to measure backlight dimming control with a high level of accuracy and ease. These tests allow us to establish

1) Whether PWM is being used to control the backlight
2) The frequency and other characteristics at which this operates, if it is used
3) Whether a flicker may be introduced or potentially noticeable at certain settings

If PWM is used for backlight dimming, the higher the frequency, the less likely you are to see artefacts and flicker. The duty cycle (the time for which the backlight is on) is also important and the shorter the duty cycle, the more potential there is that you may see flicker. The other factor which can influence flicker is the amplitude of the PWM, measuring the difference in brightness output between the 'on' and 'off' states. Please remember that not every user would notice a flicker from a backlight using PWM, but it is something to be wary of. It is also a hard thing to quantify as it is very subjective when talking about whether a user may or may not experience the side effects.

100%                                                  50%                                                  0%
 
Above scale = 1 horizontal grid = 5ms

At 100% brightness a constant voltage is applied to the backlight. As you reduce the brightness setting to dim the backlight a Direct Current (DC) method is used, as opposed to any form of PWM. This applies to all brightness settings from 100% down to 0%. The screen is flicker free as a result, as advertised.

For an up to date list of all flicker-free (PWM free) monitors please see our Flicker Free Monitor Database.

Contrast Stability and Brightness

The brightness control gave us a very good range of adjustment. At the top end the maximum luminance reached 331 cd/m² which was only a little shy of the specified maximum brightness of 350 cd/m² from the manufacturer. There was a decent 275 cd/m² adjustment range in total, and so at the minimum setting you could reach down to a low luminance of 56 cd/m². This should be adequate for those wanting to work in darkened room conditions with low ambient light. A setting of 21 in the OSD menu should return you a luminance of around 120 cd/m² at default settings. It should be noted that the brightness regulation is controlled without the need for Pulse Width Modulation, using a Direct Current (DC) method for all brightness settings between 100 and 0% and so the screen is flicker free as advertised.

We have plotted the luminance trend on the graph above. The screen behaves as it should in this regard, with a reduction in the luminance output of the screen controlled by the reduction in the OSD brightness setting. This is a linear relationship as you can see.

The average contrast ratio of the screen was excellent for an IPS-type panel with an average of 1126:1. This was mostly stable across the brightness adjustment range as shown above.

Testing Methodology

An important thing to consider for most users is how a screen will perform out of the box and with some basic manual adjustments. Since most users won't have access to hardware colorimeter tools, it is important to understand how the screen is going to perform in terms of colour accuracy for the average user.

We restored our graphics card to default settings and disabled any previously active ICC profiles and gamma corrections. The screen was tested at default factory settings using our new X-rite i1 Pro 2 Spectrophotometer combined with LaCie's Blue Eye Pro software suite. An X-rite i1 Display Pro colorimeter was also used to verify the black point and contrast ratio since the i1 Pro 2 spectrophotometer is less reliable at the darker end.

Targets for these tests are as follows:

• CIE Diagram - validates the colour space covered by the monitors backlighting in a 2D view, with the black triangle representing the displays gamut, and other reference colour spaces shown for comparison

• Gamma - we aim for 2.2 which is the default for computer monitors

• Colour temperature / white point - we aim for 6500k which is the temperature of daylight

• Luminance - we aim for 120 cd/m², which is the recommended luminance for LCD monitors in normal lighting conditions

• Black depth - we aim for as low as possible to maximise shadow detail and to offer us the best contrast ratio

• Contrast ratio - we aim for as high as possible. Any dynamic contrast ratio controls are turned off here if present

• dE average / maximum - as low as possible. If DeltaE >3, the color displayed is significantly different from the theoretical one, meaning that the difference will be perceptible to the viewer. If DeltaE <2, LaCie considers the calibration a success; there remains a slight difference, but it is barely undetectable. If DeltaE < 1, the color fidelity is excellent.

Default Performance and Setup

Default settings of the screen were as follows:

Asus ROG Swift PG279Q - Default Settings

  

Initially out of the box the screen was set in the default 'Racing mode' GameVisual preset. You could tell the screen was using a standard gamut backlight and the image looked good to the naked eye, but too bright for comfortable use. Colour balance felt pretty good, and the image quality was decent. We went ahead and measured the default state with the i1 Pro 2.

The CIE diagram on the left of the image confirms that the monitors colour gamut (black triangle) is roughly equal to the sRGB colour space. There is some minor over-coverage in all shades but not by anything significant. Default gamma was recorded at 2.3 average, leaving it with a small 4% deviance from the target which was good. The screen is lacking any gamma settings in the OSD menu so you are unable to alter the gamma without changing it at a graphics card level or through profiling with a calibration tool. Thankfully the default gamma is pretty close to the desired 2.2 though or this could have been a pain to correct for many users.

White point was measured at 6206k being slightly too warm from the target of 6500k but with a low 5% deviance. The screen was set in the default 'user' colour temp mode incidentally with RGB all set at their default levels of 100. We tested the other modes which returned the following colour temperature results:

These preset colour temperature modes behaved quite strangely, with "normal" being noticeably cool in practice, and the "warm" mode actually still being a little too cool for our 6500k target. You can at least manually change the RGB settings for calibration which we will look at in the following sections, but out of the box you're best sticking with the "user" mode.

Luminance was recorded at a very bright 291 cd/m² which is too high for prolonged general use. The screen was set at a default 80% brightness in the OSD menu but that is easy to change of course to reach a more comfortable setting without impacting any other aspect of the setup. The black depth was 0.26 cd/m² at this default brightness setting, giving us an excellent static contrast ratio (for an IPS-type panel) of 1124:1. Colour accuracy was excellent as well with a dE average of only 1.1 and maximum of 1.7. We tested the sRGB preset mode as well out of interest. It was basically the exact same results as shown above, except that the brightness was now greyed out and capped with a luminance of only 144 cd/m² which you cannot change. Testing the screen with colour gradients revealed smooth gradients with only some minor gradation evident in darker tones as you see from most screens.

Optimum OSD Adjustments

Having tested the various settings and preset modes we thought it would be useful to summarise what we would consider to be the optimum OSD adjustments out of the box, before any calibration device is used to profile the screen. These are designed to help you reach a more comfortable and reliable setup without the need for a calibration tool. In the following section we will calibrate the screen properly and provide a calibrated ICC profile for those who would like to try it.

Asus ROG Swift PG279Q - Optimum OSD settings

We used the RGB controls in the OSD to correct the white point and bring it from our slightly too warm default (6206k, 4% out) to a very close 6522k here. We had corrected the luminance as well thanks to the adjustment to the brightness control. The contrast ratio had dropped a bit due to the changes to the RGB levels, but was still very respectable for an IPS-type panel at 991:1. Gamma remains a few % out from our target at 2.3 average since there is no actual setting for gamma in the menu. Colour accuracy remained very good with dE of only 0.9 average here.

Calibration

We used the X-rite i1 Pro 2 Spectrophotometer combined with the LaCie Blue Eye Pro software package to achieve these results and reports. An X-rite i1 Display Pro colorimeter was used to validate the black depth and contrast ratios due to lower end limitations of the i1 Pro device.

Asus ROG Swift PG279Q - Calibrated Settings

   

All the OSD changes from the previous section allowed us to obtain an optimum hardware starting point and setup before software level changes would be made at the graphics card level. We left the  LaCie software to calibrate to "max" brightness which would just retain the luminance of whatever brightness we'd set the screen to, and would not in any way try and alter the luminance at the graphics card level, which can reduce contrast ratio. These adjustments before profiling the screen would help preserve tonal values and limit banding issues. After this we let the software carry out the LUT adjustments and create an ICC profile.

Average gamma was now corrected to 2.2 average, correcting most of the 4% deviance we'd seen out of the box. The white point had already been corrected nicely in the previous section through adjustments to the OSD RGB levels. It was maintained at an accurate level, measured at 6483k (0% deviance). Luminance had been improved thanks to the adjustment to the brightness control and was now being measured at 119 cd/m². This left us a black depth of 0.12 cd/m² and maintained a very good static contrast ratio (for an IPS-type panel) of 989:1. Colour accuracy of the resulting profile was very good, with dE average of 0.3 now. Testing the screen with colour gradients revealed mostly smooth gradients with some minor gradation evident in darker tones as you see from most screens, and some minor banding introduced due to the gamma correction at the graphics card level.

You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.

Calibration Performance Comparisons

The comparisons made in this section try to give you a better view of how each screen performs, particularly out of the box which is what is going to matter to most consumers. When comparing the default factory settings for each monitor it is important to take into account several measurement areas - gamma, white point and colour accuracy. There's no point having a low dE colour accuracy figure if the gamma curve is way off for instance. A good factory calibration requires all 3 to be well set up. We have deliberately not included luminance in this comparison since this is normally far too high by default on every screen. However, that is very easily controlled through the brightness setting (on most screens) and should not impact the other areas being measured anyway. It is easy enough to obtain a suitable luminance for your working conditions and individual preferences, but a reliable factory setup in gamma, white point and colour accuracy is important and not as easy to change accurately without a calibration tool.

From these comparisons we can also compare the calibrated colour accuracy, black depth and contrast ratio. After a calibration the gamma, white point and luminance should all be at their desired targets.

Default setup of the screen out of the box was very good overall, with an accurate gamma curve, reasonably close white point and very low dE. White point was slightly too warm but only by a minor 5% deviance, but contrast ratio was strong for an IPS panel. It's easy actually to obtain a better setup even without a calibration device if you follow our recommended OSD settings to correct the white point slightly.

The default setup of the TN Film based PG278Q was slightly better if you refer only to these measurements, with gamma and white point being spot on to the targets. However, you can't rely entirely on measurements with a colorimeter to give you a full picture of how the screens image will look. The main difference between the PG278Q TN Film and the PG279Q IPS is down to the viewing angles. The TN Film panel is far more restrictive in this area, showing more obvious contrast and colour tone shifts across the screen as you change your line of sight. Some people argue it won't matter if you're just viewing the screen head on anyway and that's true to a point. However, even if you are viewing it head on, as you glance to the sides, or particularly as you glance up or down vertically, there are subtle colour tone and contrast shifts caused by the pixel alignment of the technology. This isn't really a problem for general uses and gaming, but if you were doing any colour critical work or photo editing it is not really suitable. The IPS panel of the PG279Q shows a far more stable image thanks to the differing panel technology, and does not suffer from these viewing angle issues. As a result, while the figures might suggest the PG278Q is better out of the box, in reality the image quality and stability are better from the IPS PG279Q.

The overall setup and image quality was pretty similar to the Asus MG279Q, and both were a bit better than the Acer Predator XB270HU's default setup.

The display was strong when it came to black depth and contrast ratio for an IPS-type panel. With a calibrated contrast ratio of 989:1 it was comparable to some of the better screens using this kind of panel technology. It was not quite as high as the Dell U2515H (1138:1) which holds the record for an IPS contrast ratio. The contrast ratio was better than the TN Film PG278Q by a reasonable amount as well which was pleasing. Of course none of these IPS screens can compete with VA panel types which can reach over 2000:1 easily, and even close to 5000:1 in the case of the 24" Eizo FG2421 shown here.

Viewing Angles

Above: Viewing angles shown from front and side, and  from above and below. Click for larger image

Viewing angles of the PG279Q were very good as you would expect from an IPS panel. Horizontally there was very little colour tone shift until wide angles past about 45°. A slight darkening of the image occurred horizontally from wider angles as you can see above as the contrast shifted slighting. Contrast shifts were slightly more noticeable in the vertical field but overall they were very good. There was some slight pink tone introduced from wide vertical angles. The screen offered the wide viewing angles of IPS technology and was free from the restrictive fields of view of TN Film panels, especially in the vertical plane. It was also free of the off-centre contrast shift you see from VA panels and a lot of the quite obvious gamma and colour tone shift you see from some of the modern VA panel type offerings. All as expected really from a modern IPS panel.

This is one of the big positives of using IPS panel technology as opposed to the common TN Film matrices which are generally adopted in gaming displays. If you compare the viewing angles to the TN Film based PG278Q you can see the obvious differences, especially vertically. As we said in the previous section some people argue it won't matter if you're just viewing the screen head on anyway and that's true to a point. However, even if you are viewing it head on, as you glance to the sides, or particularly as you glance up or down vertically, there are subtle colour tone and contrast shifts caused by the pixel alignment on the TN Film panel. This isn't really a problem for general uses and gaming, but if you were doing any colour critical work or photo editing it is not ideal. The IPS panel of the PG279Q shows a far more stable image thanks to the differing panel technology, and does not suffer from these viewing angle issues. This is also important should you want to use the screen for gaming from a distance, where your viewing position may vary more, or where you may have additional players who can't view the screen as head on as you. Likewise for movie viewing the changing angles of view can be problematic on a TN Film panel. Those issues are not as much of a problem on the IPS panel of the PG279Q.

Above: View of an all black screen from the side. Click for larger version

On a black image there is a characteristic white glow when viewed from an angle, commonly referred to as "IPS-glow". This is common on most modern IPS-type panels and can be distracting to some users. The level of glow here is the same as the other recent high refresh rate IPS panels we've seen like the Acer XB270HU and Asus MG279Q and is pretty typical of a modern IPS-type panel. If you view dark content from a normal head-on viewing position, you can actually see this glow slightly as your eyes look towards the edges of the screen. Some people may find this problematic if they are working with a lot of dark content or solid colour patterns. In normal day to day uses, office work, movies and games you couldn't really notice this unless you were viewing darker content. If you move your viewing position back, which is probably likely for movies and games, the effect reduces as you do not have such an angle from your eye position to the screen edges.

This is one area where the TN Film panel of the PG278Q is better, as there is far less pale glow from an angle on dark content. For dark room conditions, and a lot of dark content some people might prefer to live with the more restrictive viewing angles and less glow of the TN Film panel. Others might want to use the screen for more all-round uses and prefer the IPS panel. It's down to preference really and your individual uses.

Above: demonstrating IPS-glow commonly confused with backlight bleed. Click for larger version

We want to make a point at this stage relating to IPS glow. The above image shows the corners of the screen as observed from a central viewing position, at a normal viewing distance of a couple of feet from the screen. As you look towards the corners of the screen you can see a glow and pale areas on the dark content. This is not backlight bleed! We see many reports of users who mistake IPS glow which is a panel characteristic, for backlight bleed which is a build quality issue. This glow in the corners is caused by your angle of vision when viewing the screen and is because of the pixel structure on the IPS panel. If you view the screen from even wider angles (like the image shown above it) the glow becomes more white and pale. This IPS glow is a "feature" of nearly every IPS-type panel on the market, so as a buyer you should be expecting it. It's not grounds for a return of the screen as a fault when it is just a feature of the panel technology. The bigger the screen, and the wider the field of view, the more obvious this glowing from the corners will be. On a 34" ultra-wide screen for instance there are very wide fields of view and so you will notice it when sat up close to the screen and viewing dark content. It's not as pronounced on a 16:9 format 27" screen like this but may still be problematic to some people, especially if you use the screen in a darkened room or are viewing a lot of dark content. If you move your viewing position back a bit, it will be reduced.

Above: the same side of the screen but viewed head on and from a metre or so back. Click for larger version

If you move your viewing position back a metre or so and view that side of the screen head on as shown above, the glow has disappeared. You can tell there's barely any clouding or bleed from the backlight in these corners. So what was previously thought of as bleed, actually isn't at all.

Panel Uniformity

We wanted to test here how uniform the brightness was across the screen, as well as identify any leakage from the backlight in dark lighting conditions. Measurements of the luminance were taken at 35 points across the panel on a pure white background. The measurements for luminance were taken using BasICColor's calibration software package, combined with an X-rite i1 Display Pro colorimeter with a central point on the screen calibrated to 120 cd/m². The below uniformity diagram shows the difference, as a percentage, between the measurement recorded at each point on the screen, as compared with the central reference point.

It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.
 

Uniformity of Luminance

The luminance uniformity of the screen was moderate. The screen was darker along the top edge for some reason, where luminance dropped down by 29% to 93 cd/m² in the most extreme cases. The central and lower areas of the screen were more uniform though, and overall 63% of the screen was within a 10% deviance of the centrally calibrated point.

Backlight Leakage

Above: All black screen in a darkened room. Click for larger version

As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. The camera showed there was some clouding detected in the corners, but it was slight and pretty hard to spot in normal uses unless you specifically went looking for it on black screens in a dark room. It should not present any problems in regular use.

General and Office Applications

The PG279Q feature a large 2560 x 1440 WQHD resolution, a significant step up from the wide range of 1920 x 1080 screens on the market, especially when you compare it to the 27" gaming screens around with only 1080p support. The pixel pitch of 0.233 mm is quite small as a result, and by comparison a standard 16:10 format 24" model has a pixel pitch of 0.270mm and a 30" model has 0.250mm. These ultra-high resolution 27" models offer a tight pixel pitch and therefore small text as well. We found it quite a change originally coming from 21.5 - 24" sized screens back in the day, even those offering quite high resolutions and small pixel pitches. Although now we are very used to working with 27" 1440p screens all the time and find them very comfortable and a significant upgrade over 1080 / 1200p models. Some users may find the small text a little too small to read comfortably, and we'd advise caution if you are coming from a 19" or 22" screen for instance where the pixel pitch and text are much larger. The extra screen size takes some getting used to over a few days as there really is a lot of room to work with but once you do, it's excellent. For those wanting a high resolution for CAD, design, photo work etc, this is a really good option. The image was very sharp and crisp and text was very clear. With its WQHD display, you enjoy 77% more desktop space than a full HD screen to spread out your windows and palettes.

The thin bezel design mean that the PG279Q could be easily integrated into a multi-screen set up if you wanted. The light AG coating of the modern AHVA (IPS-type) panel is certainly welcome, and much better than the older grainy and 'dirty' appearance of older IPS AG coatings. It is also less grainy than the TN Film coating in the PG278Q model. The wide viewing angles provided by this panel technology on both horizontal and vertical planes, helps minimize on-screen colour shift when viewed from different angles and as we've already covered this is a significant improvement over TN Film panels. The default setup of the screen was very good, offering a decent gamma curve, reasonable white point, strong contrast ratio and very low dE. Correcting the white point is easy through a couple of RGB changes in the menu, and even without calibration we thought the image looked decent for day to day office work.

The brightness range of the screen was also very good, with the ability to offer a luminance between 331 and 56 cd/m². This should mean the screen is perfectly useable in a wide variety of ambient light conditions, including darkened rooms. A setting of ~21 in the OSD brightness control should return you a luminance close to 120 cd/m² out of the box. On another positive note, the brightness regulation is controlled without the need for the use of the now infamous Pulse-Width Modulation (PWM), and so those who suffer from eye fatigue or headaches associated with flickering backlights need not worry.

There was a very slight audible buzzing from the screen, but only if you listened very closely to it. Certainly nothing you could detect in normal use from a normal distance. The screen also remains cool even during prolonged use. There is no specific preset mode for office work or reading but you could set up one of the other modes to your liking if you wanted something a little different for reading.

The screen offers 2x USB 3.0 ports which can be useful and it was nice to keep this up to date with the modern version, but both are located on the back of the display so are not easy-access really. Integrated speakers can provide sound for the odd YouTube clip or mp3 if you want. There are no further extras like ambient light sensors or card readers which can be useful in office environments. Remember, this is aimed at gamers really. There was a great range of ergonomic adjustments available from the stand allowing you to obtain a comfortable position for a wide variety of angles. They were mostly pretty stiff though so you might not want to move it around too often. The VESA mounting support may also be useful to some people as well.

 
Above: photo of text at 2560 x 1440 (top) and 1920 x 1080  (bottom)

The screen is designed to run at its native resolution of 2560 x 1440 and at a 144Hz native refresh rate. However, if you want you are able to run the screen outside of this resolution. We tested the screen at a lower 1920 x 1080 resolution to see how the screen handles the interpolation of the resolution, while maintaining the same aspect ratio of 16:9. At native resolution the text was very sharp and clear. When running at a 1080p resolution the text is still reasonably clear, with moderate levels of blurring. You do lose a lot of screen real-estate as well of course but the image seems to be quite well interpolated if needed.

Gaming Introduction

The ROG Swift PG279Q, like the PG278Q before it, is clearly aimed at the gaming market primarily. The old model was a TN Film based offering and so was somewhat restrictive when it came to other types of uses. It had only a single DisplayPort connection as well, but did offer you G-sync, ULMB, 1ms G2G response time and 144Hz refresh rate. It was firmly a gaming screen. The PG279Q maintains a similar market position, with high-end features clearly aimed at a gaming audience. Asus have even boosted the refresh rate a little to 165Hz maximum which we will discuss in a moment. However, the switch here to an IPS-type panel opens the screen up for other uses if you want, avoiding some of the limitations that its predecessor had. The screen can therefore combine the raw gaming experience of a high end display with quality performance in other areas as well. Hopefully the best of both Worlds.

Here is a quick comparison of some of the key features and differences between the old PG278Q and new PG279Q models:

As well as G-sync support, the PG279Q features NVIDIA's Ultra Low Motion Blur (ULMB) blur-reduction backlight system. This allows for a strobing backlight to reduce perceived motion blur in dynamic content. Have a read of our blur reduction backlight article which talks about the benefits of these kind of technologies in more detail. It's a feature some people really like when it comes to dynamic content, primarily gaming. It can really help reduce the motion blur you see on the screen due to the way LCD technology operates. As with other screens which support ULMB, it cannot be used at the same time as G-sync since that operates with a dynamic refresh rate by its nature. You can enable ULMB if you would rather use that to G-sync when your screen is set to 85, 100 or 120Hz refresh rates. We will look at the ULMB operation in more detail later.

Although NVIDIA G-sync is offered here, NVIDIA 3D Vision is not supported unfortunately. It was available on the old PG278Q model so that is one area where that screen has the edge, if 3D is something you're interested in using.

Responsiveness and Gaming

The ROG Swift PG279Q is rated by Asus as having a 4ms G2G response time, which indicates the panel uses overdrive / response time compensation (RTC) technology to boost pixel transitions across grey to grey changes. There is user control over the overdrive impulse within the OSD menu using the 'OD' (overdrive) option. The part being used is the AU Optronics M270Q008 V0 AHVA (IPS-type) panel. Have a read about response time in our specs section if you need additional information about this measurement.

We will first test the screen using our thorough response time testing method. This uses an oscilloscope and photosensor to measure the pixel response times across a series of different transitions, in the full range from 0 (black) to 255 (white). This will give us a realistic view of how the monitor performs in real life, as opposed to being reliant only on a manufacturers spec. We can work out the response times for changing between many different shades, calculate the maximum, minimum and average grey to grey (G2G) response times, and provide an evaluation of any overshoot present on the monitor.

We use an ETC M526 oscilloscope for these measurements along with a custom photosensor device. Have a read of our response time measurement article for a full explanation of the testing methodology and reported data.

Response Time Setting Comparison

The ROG Swift PG279Q comes with a user control for the overdrive impulse available within the OSD menu in the 'image' section. There are 3 options available here under the OD setting. First of all we carried out a fairly small set of measurements and motion tests in all 3 of the OD Mode settings for the purposes of identifying which was the optimum response time setting. There tests were conducted at 144Hz refresh rate.

Firstly we tested the response times with OD set to off, effectively turning off the overdrive impulse. The average response time was measured at 10.3ms G2G average which was actually not that slow, but certainly not optimum for this technology. Rise times were quite a bit slower than fall times and there was some obvious blurring to moving images. There was no overshoot in this mode since OD was turned off, but we would hope for better responsiveness from the other modes.

Switching up to the 'Normal' OD mode brought about some positive changes to response times. G2G average had reduced down to 5.2ms now which was much better, and showed significant improvements in motion tests. There was basically no overshoot in this mode as well which was great news.

Finally we tested the 'Extreme' OD mode. There was an improvement in measured response times down to 4.0ms G2G average. However, it was at the cost of some insane overshoot, which was obvious and distracting during actual use. Stick with the 'normal' OD mode.

Refresh Rate

One of the key features of the ROG Swift PG279Q is the high refresh rate. The panel itself is designed to run at 144Hz by AU Optronics and that's the native refresh rate you will be able to select in Windows when you first connect the screen. That refresh rate can be used from AMD cards as well as NVIDIA and is a high native refresh rate which is very useful for gaming and improved motion fluidity. We tested the response time performance while running the screen at different refresh rates as we've seen in the past that refresh rate can sometimes influence the response times and overshoot. The below tests were based on using the 'normal' OD setting which we have already established is the optimum.

As you can see, there is a decent improvement in pixel response times as you increase the refresh rate. At 60Hz, the screen behaves like the best IPS-type panels we've seen at the moment, reaching down to 8.5ms G2G and with no overshoot. That is about as good as you can get from a current 60Hz IPS panel in any display. As you increase the refresh rate, the response times reduce. By the time you reach the maximum 144Hz native refresh rate the response times are as low as 5.2ms G2G with only very minor (not noticeable at all) overshoot introduced. This performance is faster even than we'd seen from the Acer XB270HU at 144Hz (5.9ms G2G average) and is a very good performance from an IPS-type panel. The fact there's no noticeable overshoot is excellent.

If you use OD 'off' the response times are much slower and there's far more blurring to the moving image. Again there's some improvements in response times as you increase the refresh rate but even at 144Hz they are slow (10.3ms G2G) so we wouldn't recommend using that mode. The 'extreme' setting is just too aggressive and there's lots of noticeable overshoot, less so at 60Hz but really very obvious as you increase the refresh rate up.

So what does this all mean? Well it means that the pixel response times of the screen will vary a little depending on the refresh rate you're using. If you plugged in a 60Hz console, the response times would be ~8.5ms G2G, still very good for an IPS panel. If you use G-sync and the refresh rate fluctuates between 30 and 144Hz, the response times are controlled dynamically and will vary a little as refresh rate changes. To be honest we aren't talking huge differences, although when you combine the slightly higher response time impact on blurring, with the impact of lower refresh rates on perceived blur, you will notice some difference in motion clarity depending on your active refresh rate. The variation in response times isn't really a big factor, and you're more likely to notice the difference in motion clarity caused by the changes in refresh rate anyway. It's just an interesting thing to note. The same thing happened on the Acer XB270HU display, but not on the Asus MG279Q despite the use of the same panel in each display. It seems that the G-sync module is perhaps responsible for dynamically controlling the response times with refresh rate, whereas the FreeSync MG279Q display did not show this.

Overclocking

One of the most notable new features of the PG279Q is the overclocked refresh rate. We saw something similar when we tested the Acer Predator X34 recently, where Acer had allowed you to overclock from the native 60Hz up to an impressive 100Hz. This worked well in our tests, providing a nice boost in frame rates, responsiveness and overall gaming experience. Asus have offered something similar here, although with a more modest boost of 21Hz, from 144Hz up to 165Hz. This appears to be possible thanks to the addition of the G-sync module, or perhaps more because of the lack of any in-built scaler on the monitor. Either way, the new overclockable monitors emerging in the market all have G-sync in common so that appears to be a key requirement to enable this.

Up front you probably need to think about whether this additional 21Hz is really going to make a difference in practice. You'd need a very powerful system and graphics card to be able to output up to 165fps at 2560 x 1440 with decent settings. 144Hz (the native refresh rate) is probably a challenge as it is, so driving up to 165Hz is a massive demand. We can understand the benefits when you talk about overclocking a 60Hz panel up to 100Hz (like with the Acer Predator X34) but here, we're talking at the very high refresh rate end already. Even if you can power that kind of frame rate reliably, whether you'd see any real difference in practice between 144 and 165Hz is also questionable. It does seem to be little more than a marketing gimmick really in our opinion. Maybe some people will reach those levels and find it useful, but to be honest it feels to us a bit like a race to offer the highest number in the spec.

Above: with thanks to Asus for sending us an NVIDIA GTX980 for testing the overclocking feature

The overclocking feature can be quickly enabled via the OSD menu as shown above. Once you've turned it on, a slider allows you to specify what you want the maximum refresh rate to be with steps available of 144, 150, 155, 160 and 165Hz. You can choose the maximum level here presumably because results could vary from one system to another. Asus don't guarantee the overclocked refresh rate and indeed the ability to support anything above 144Hz is limited to your graphics card. You need an NVIDIA GTX960 or above graphics card to use the overclocking feature, so older NVIDIA cards and other manufacturers like AMD will be limited to "only" 144Hz. We say limited, but it's hardly low is it?! Anyway, you need a GTX960 or above to use this feature. Once you enable the overclocking feature, the G-sync range can extend up to whatever you set as the maximum, so you could in theory have G-sync between 30 and 165Hz as the maximum supported range. The overclocked refresh rate has no bearing on ULMB support though as that can only be used when running at 85, 100 or 120Hz refresh rates.

One important note people should realise is that if you enable the overclocking feature in the OSD menu and are using a card lower than a GTX960 the monitor will report back to Windows that the maximum refresh rate is only 120Hz. If you disable the overclocking option again, you should be able to select 144Hz without any issue, as that's the native refresh rate supported by the panel. So only enable overclocking if you have a compatible graphics card and are pushing it above 144Hz. Likewise if you use a GTX960 or higher, the new maximum overclocked refresh rate will be available to select, but the next step down will be 120Hz. You will lose the 144Hz setting for some reason.

Above: Windows refresh rate settings once overclocking has been enabled in the OSD menu

Once it has restarted, you will see additional refresh rate settings available in Windows to choose from, at whatever you set as the maximum in the OSD menu. You simply just select the setting you want and that's it!

The active resolution and refresh rate are confirmed in the information section of the OSD menu as well at the top.

One of the most important tests for an overclocked refresh rate is whether it can support that without dropping frames. We tested the screen using the BlurBusters.com frame skipping test and were very pleased to see that no frames were dropped at all, even at the maximum 165Hz refresh rate. This overclocking seemed to work very well, at least from our test system and we were impressed.

One area which wasn't quite as good though was the response times. We tested these again at 165Hz and compared them to our measurements we had taken at the optimum 144Hz refresh rate earlier. As a reminder, we found that as you increase the refresh rate from 60Hz to 144Hz, the response times improved as you went. The response times and overdrive impulse are dynamically controlled by the G-sync module it seems, and influenced by the active refresh rate. We hoped for a further improvement with the boost to 165Hz but actually the opposite was the case.

The response times were slightly slower overall at 165Hz than they had been at 144Hz. The average G2G was now 6.0ms instead of 5.2ms at 144Hz. This translated to a small amount of increased motion blur, but we're talking very very slight. This is arguably offset anyway by the slight improvement in motion clarity brought about by the higher frame rate / higher refresh rate.

Above: Transition from 0-150 at 144Hz refresh rate

If we look specifically at one measurement, from 0 - 150 you can see what is happening more clearly. The above graph represents a change in brightness from black (0) along the bottom flat green line, to middle grey (150) along the upper flat(ish) green line. Those are the two shades being compared, 0 and 150. The time it takes to change between the two shades is the response time. We take an allowance of 10% on either side, so we measure the response time from the point where there has been a 10% change already, to where it reaches 90% of the desired brightness. This is a standard measurement process for panel manufacturers when measuring pixel response times. So the horizontal blue and red lines represent those points. The blue horizontal line representing the brightness 10% in to the change from black (0) to grey (150), and the red line representing the brightness when it reaches 90% of the desired shade. We then measure the distance between those two lines, shown by the two vertical lines and that is the response time.

At 144Hz as shown above, this particular transition from 0-150 has a response time of 5.3ms.

Above: Transition from 0-150 at 165Hz refresh rate

If we run the exact same test but at a 165Hz refresh rate the graph changes a bit. You can see that the distance between the two vertical lines is now greater, and this represents a response time of 10.8ms now.

The reason for the difference seems to be down to the overdrive impulse and the way it is being applied. You can see that at 165Hz the brightness change tales off when it reached about 80% of the desired brightness and then takes a bit longer to reach that 90% threshold, whereas at 144Hz is pushed the brightness change more quickly. This tailing off the overdrive impulse is designed to avoid overshooting the required brightness level, which in itself causes problems with trails, ghosting and dark/pale overshoot artefacts if not done. So it seems that at the overclocked 165Hz refresh rate the overdrive impulse is not being applied as aggressively and so response times are a little slower.

We should point out that this is hardly a big change, and as we say, the slightly slower response times are probably offset in actual performance by the slightly improved motion clarity from the higher refresh rate. Try the screen out with and without overclocking enabled and see how you get on. The main take-away here is that the 165Hz support is not really a great improvement over 144Hz in our opinion. You'll probably struggle to reach that kind of frame rate anyway, and if you do, the extra 21Hz is hardly worth it when you take into account the slightly slower response times as well. The screen is just as good at 144Hz so don't worry if you're an AMD user or someone with an NVIDIA card less than a GTX960, you aren't missing much.

More Detailed Measurements
OD Normal, 144Hz Refresh Rate

Having established that the OD normal setting offered the best response/overshoot balance we carried out our normal wider range of measurements as shown below. We used the maximum default refresh rate of 144Hz since that should be achievable for every user and we had found the overclocked refresh rates delivered a slightly slower response time performance anyway.

The average G2G response time was more accurately measured at 5.0ms which was excellent IPS-type panel. Transitions were very stable across all the changes, whether they were changes from dark to light (rise times) or from light to dark (fall times). Overall the response times were faster than the best 60Hz IPS panels available at the moment, which can reach down to about 8.5ms G2G average without overshoot. Here, the 144Hz refresh rate helped push them a lot lower which was pleasing. 5.0ms G2G is an excellent achievement for an IPS panel.

There was basically no noticeable overshoot on any transition with only very minor amounts recorded by our oscilloscope. Excellent response times, without any noticeable overshoot. Well done AU Optronics and Asus!
 

Display Comparisons

The above comparison table and graph shows you the lowest, average and highest G2G response time measurement for each screen we have tested with our oscilloscope system. There is also a colour coded mark next to each screen in the table to indicate the RTC overshoot error, as the response time figure alone doesn't tell the whole story.

When using the screen at the native 144Hz refresh rate the response times of 5.0ms G2G surpassed the previous high refresh rate IPS panels we've tested, namely the Acer XB270HU (5.5ms) and Asus MG279Q (6.5ms). This was an impressive performance and there was basically no overshoot introduced either to worry about. These response times are faster than all the 60Hz IPS panels available, which top out at about 8.5ms G2G at best (without overshoot). There's therefore an improvement in response time blurring levels, as well as a big improvement in motion clarity brought about by the high refresh rate. These 144Hz IPS panels are certainly much faster and more suited to gaming than the 60Hz IPS panels around.

If you compare the PG279Q then with some of the fast TN Film models there are two main differences. The fast TN Film panels like the ROG Swift PG278Q (2.9ms) and BenQ XL2730Z (3.4ms) have slightly faster response times. However, they do both show moderate levels of overshoot so you sacrifice somewhat to drive the response times lower. We feel that the freedom of overshoot and the generally all-round better image quality of the PG279Q makes it a better choice than the TN Film models in our opinion. Some may find that the motion clarity feel of the TN Film panels is their preference, but the majority of users will probably find the fast IPS panels better overall.

The screen was also tested using the chase test in PixPerAn for the following display comparisons. As a reminder, a series of pictures are taken on the highest shutter speed and compared, with the best case example shown on the left, and worst case example on the right. This should only be used as a rough guide to comparative responsiveness but is handy for a comparison between different screens and technologies as well as a means to compare those screens we tested before the introduction of our oscilloscope method.

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (OD = Normal)

In practice the Asus ROG Swift PG279Q performed best with OD at normal. There were low levels of blurring evident, the image looked sharp and there was no overshoot at all. The support for higher refresh rates up to 145Hz provided additional levels of motion clarity and image smoothness which surpassed what was possible from 60Hz panels. The additional G-sync support for NVIDIA users will also be of real benefit.

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (OD = Normal)

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (OD = Normal)

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (Trace Free = 80)

The above images compare the PG279Q with the two other high refresh rate IPS-type panels we've tested. In practice there is very little to separate these 3 at all. The response time measurements in the previous section show that the PG279Q has the slight edge, and you can notice some minor improvements in motion clarity compared with the MG279Q in these images as well. All 3 are very good and show no real overshoot.

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (OD = Normal)

27" 1ms G2G AU Optronics TN Film @ 144Hz (OD = Normal)

27" 1ms G2G AU Optronics TN Film @ 144Hz (AMA = High)

27" 8ms G2G LG.Display AH-IPS (Response Time = Normal)

The above then compares the PG279Q with a few other popular models. You will see the comparison first of all against the old PG278Q TN Film model and then the similarly fast BenQ XL2730Z display. Those two have faster response times but show some moderate levels of overshoot, detected here as the dark trails behind the moving car. It's a trade off really to get slightly faster response times. The popular Dell U2715H is a pretty decent 60Hz IPS panel, but you will see more obvious blurring due to the slower response times and much lower refresh rate.

Ultra Low Motion Blur (ULMB)

The Asus PG279Q also features an integrated Blur Reduction Backlight system, dubbed "Ultra Low Motion Blur" (ULMB). We have already seen a lot of positive improvements in perceived motion blur from such systems in the past. Our in depth article from June 2013 looked at this in a lot more detail, and tested some of the original LightBoost "hacks" to achieve a strobed backlight and blur reduction benefits. Since then we've seen a quite a lot of monitors integrate a similar strobed backlight with simple user control from the menu. Like the previous PG278Q model, the PG279Q uses the ULMB feature associated with the G-sync module.

The ULMB feature is accessible from the image section of the OSD menu as shown above. It is only available when running the screen at 85, 100 and 120Hz modes. It is not available at 144Hz or any of the overclocked refresh rate, and it is also important to note that ULMB does not work when you are using G-sync, it's one or the other. When you enable the ULMB feature a new option appears for the "ULMB Pulse Width" as you can see from the screenshot above. We will test that in a moment as well, but it allows you to control the strobe length, and therefore adjust the visible persistence somewhat. You can adjust this between 100 and 10, and as you lower the setting the screen also becomes progressively darker as you reduce the "on" period of the strobe. Nice to see this included as an option within the menu for those who like to play around with the setting, much like you could do by adjusting LightBoost levels on older models using the "hack" method. There is no control to adjust the timing of the strobe to impact the strobe cross-talk it can introduce, so we will have to hope that the default timing setup is suitable.

Operation - 85Hz

ULMB backlight cycling, 85Hz (scale = 5ms)
pulse width setting= 100

We measured the screen using our oscilloscope when viewing a solid white image, with ULMB feature turned on and with refresh rate set at 85Hz. This is the lowest refresh rate at which you can operate the ULMB mode. As a reminder, it works at 85, 100 and 120Hz only. We left the pulse width (strobe length) setting at 100 initially. Normally the oscillograph would show a flat straight line when measuring a static white image (as no PWM is being used for backlight dimming), but here the ULMB feature is cycling the backlight off and on rapidly.

The time for each complete cycle is 11.76ms which shows that in this case the backlight is being cycled at the same frequency as the refresh rate, 85 times per second. The strobe is in time with the refresh rate of 85Hz.

ULMB backlight cycling, 85Hz (scale = 5ms)
pulse width setting = 50

ULMB backlight cycling, 85Hz (scale = 5ms)
pulse width setting = 10

As you reduce the pulse width setting you are adjusting the 'on' period of the strobe, shown by the top portion of each peak. As you reduce the setting the strobe 'on' time gets progressively shorter as you can see from the above 2 graphs, the first at a setting of 50 and the second at a setting of 10 (the minimum setting available). This impacts the perceived blur somewhat, with the shorter 'on' times resulting in a clearer image. At the same time though the brightness of the image is affected and it becomes very dark, the lower you go with the setting. More on that in a moment. There will be a point where the user does not see any further benefit to their eyes of reducing the strobe length further, but you can have a play around with the setting to find your personal preference to balance perceived motion blur and brightness of the image.
 

Operation - 100Hz

ULMB backlight cycling, 100Hz (scale = 5ms)
pulse width setting = 100

When running the screen at a 100Hz refresh rate the behaviour is exactly the same. The only difference is that the strobe is now synced with the new refresh rate, with a new strobe every 10ms (100 times per second).

Operation - 120Hz

ULMB backlight cycling, 120Hz (scale = 5ms)
pulse width setting = 100

Again when set at 120Hz refresh rate the strobes are in sync again, with a new strobe every 8.33ms (120 times per second).
 

Pulse Width Setting - Strobe Length

We measured the strobe length at a variety of the Pulse Width settings, while running at the maximum 120Hz refresh rate mode. You can adjust the setting in steps of 1 incidentally. Each complete strobe lasts a total of 8.33ms (120 strobes per second). This strobe timing was exactly the same as on the PG278Q incidentally:

Pulse Width Setting - Brightness Range

We tested the brightness output of the screen when ULMB was turned on. You can independently control the brightness setting as well if you want, but we left it at the default 100 and just changed the pulse width (PW) strobe length setting to establish the brightness range when using this option. With the PW setting at 100 the maximum achievable luminance of the screen was a moderate 101 cd/m². This should be enough for a lot of uses, but you cannot get a brighter display when using ULMB if you wanted to. This is a typical performance from a strobe backlight anyway and represented a decent enough luminance level. It's worth noting that the PG278Q could reach a slightly brighter state at 123 cd/m² at PW 100, but that's only because the backlight is a little stronger (max brightness recorded at 385 cd/m² on the PG278Q and 331 cd/m² on the PG279Q).

As you reduce the PW setting the luminance drops significantly, at the lowest setting probably being far too dark for any practical use. At least you can control a reasonably wide range here, so you can find a level which suits your needs. We suspect a setting of 100 will probably be adequate for most normal users anyway, as the ULMB mode certainly brings about positive improvements to the perceived motion blur.

Brightness Range (PW at 100)

We also wanted to test the brightness range when leaving PW at its default 100, and changing the brightness control of the screen instead. The table above confirms the range available through that control.
 

Colour and Other Setup Characteristics

We wanted to test the impact on the setup of the screen when enabling the ULMB feature to see whether it has a knock-on effect to white point, gamma or colour accuracy. You can see straight away that it impacts the luminance of the screen, which we've already looked at above.

Asus ROG Swift PG279Q - Calibrated Settings, ULMB Off

   

Above is our calibrated state from earlier on in the review, with the ULMB feature turned off.

Asus ROG Swift PG279Q - Calibrated Settings, ULMB On

We turned the ULMB mode on, but left the PW option at 100 here, and with the default maximum 100 brightness as well. The only change  made automatically in the OSD other than the maximum brightness is that contrast has been changed from 50 to 45. We left that at 45 and also left our calibrated ICC profile active from our initial calibration to see what immediate impact the ULMB setting had on the colour performance. The gamma and white point were skewed slightly here, with gamma now a little lower at 2.1 average (3% deviance), and white point being a little cooler at 6714k (3% out). The contrast ratio remained very similar at 922:1. The colour accuracy was also a little off with average dE of 0.9 now, maximum of 2.2. No major impact really to the appearance of the screen of the colour rendering other than the reduction in achievable luminance of course. This was pleasing as we know from testing older LightBoost strobed backlight systems that they can really impact the colours and white point of a screen when enabled.

Blur Reduction Tests

Of course the main thing we want to test is what improvements the Blur Reduction mode offers when it comes to motion clarity and gaming. We were pleased with the results we'd seen from LightBoost backlights when we tested them, and also from the natively supported blur reduction feature on other displays including the previous PG278Q model and the competing Acer XB270HU (which also has ULMB). Our pursuit camera tests in the following section give you a good indication of perceived motion blur with and without ULMB enabled.

We were very pleased with the results here as we had been on other blur reduction displays, with an obvious and marked improvement in perceived motion blur experienced. Tracking of moving objects became much easier and the image looked sharper and clearer. We used the BlurBusters full-screen TestUFO online motion test (all ULMB supported refresh rates) as well to put the feature through its paces and were pleased with the results. The upper half of the screen was a little clearer than the bottom, and in the bottom third of the screen some strobe cross-talk became apparent. It is impossible to eliminate strobe cross-talk completely due to the way they operate, but the important thing is whereabouts on the screen this manifests itself and to what level. The central region is probably the most important since that's where a lot of your gaming focus will be, where crosshairs and the likes are. We were pleased that there was minimal cross-talk here in the central region and the image looked very good. Having the ability to alter the strobe length through the PW setting was also very useful, and you could tweak it to your preference to reduce even more of the persistence if you wanted, as long as you didn't mind sacrificing some brightness.

Another very good implementation of a strobe backlight system here, we were impressed. We suppose the only minor quibble is the inability to operate the feature at 144Hz or in an ideal World, at the same time as using G-sync.

Pursuit Camera Tests

We've already tested above the actual pixel response times and other aspects of the screen's gaming performance. We wanted to carry out some pursuit camera tests as well to give an even more complete idea of the performance of this screen.

Pursuit cameras are used to capture motion blur as a user might experience it on a display. They are simply cameras which follow the on-screen motion and are extremely accurate at measuring motion blur, ghosting and overdrive artefacts of moving images. Since they simulate the eye tracking motion of moving eyes, they can be useful in giving an idea of how a moving image appears to the end user. It is the blurring caused by eye tracking on continuously-displayed refreshes (sample-and-hold) that we are keen to analyse with this new approach. This is not pixel persistence caused by response times; but a different cause of display motion blur which cannot be captured using static camera tests. Low response times do have a positive impact on motion blur, and higher refresh rates also help reduce blurring to a degree. It does not matter how low response times are, or how high refresh rates are, you will still see motion blur from LCD displays under normal operation to some extent and that is what this section is designed to measure. Further technologies specifically designed to reduce perceived motion blur are required to eliminate the blur seen on these type of sample-and-hold displays which we will also look at.

We used the Blurbusters.com Ghosting Motion Test which is designed to be used with pursuit camera setups. The pursuit camera method is explained at BlurBusters as well as covered in this research paper. We carried out the tests at various refresh rates, with and without Blur Reduction enabled. These UFO objects were moving horizontally at 960 pixels per second, at a frame rate matching refresh rate of the monitor.

OD Setting Normal

These tests capture the kind of blurring you would see with the naked eye when tracking moving objects across the screen. As you increase the refresh rate the perceived blurring is reduced, as refresh rate has a direct impact on motion blur. It is not eliminated entirely due to the nature of the sample-and-hold LCD display and the tracking of your eyes. No matter how fast the refresh rate and pixel response times are, you cannot eliminate the perceived motion blur without other methods. Fortunately there is a Blur Reduction (ULMB) mode available from this screen so you are able to reduce perceived motion blur further using a strobe backlight. The above should give you an idea of the kind of perceived motion blur range when using the screen without ULMB, including when connecting an external device (60Hz only) or when using G-sync (here, ranging between 60 and 144Hz)

Note: optimal overdrive settings used on each screen

We can also compare the pursuit camera tests at 60Hz and 144Hz compared with a couple of very fast and very popular gaming screens above. The performance is very comparable in actual perceived motion blur between all three in practice, with very little to separate them. The TN Film PG278Q feels ever so slightly more fluid we felt, thanks to the slightly faster response times. However you do have to live with moderate low levels of overshoot in places. For us, we prefer the two IPS screens here, with the Asus PG279Q having the edge.

We left the strobe pulse width length at maximum setting here as it has an impact on brightness if you lower it, in an attempt to reduce motion blur even further. We felt the results were very good without needing to reduce the strobe length anyway here. With ULMB enabled the backlight is strobed briefly, once per refresh, for low persistence. The brief backlight flash prevents tracking-based motion blur and the moving object is far easier to see when tracking it across the screen with your eyes (or by the pursuit camera). There is extremely little leftover ghosting caused by pixel transitions (virtually invisible to the human eye), since nearly all (>99%+) pixel transitions, including overdrive artefacts, are now kept unseen by the human eye, while the backlight is turned off between refreshes.

The clarity of the moving image is improved significantly and tracking across the screen with your eye is much easier and clearer. You will note there is some cross talk evident here in the form of the trailing image, and a result of the strobe timing. These images were taken at the centre of the screen vertically, so it gives you a good indication also of the strobe cross-talk levels on this display, in the central region. In the middle region of the screen it is at low/moderate levels but is not too bothersome in practice. The cross-talk is reduced as you increase the refresh rate as well which is pleasing. These tests give you a good visual indication of the improvements which ULMB can bring in perceived motion blur.

Additional Gaming Features

Lag

For the full reviews of the models compared here and the dates they were written (and when screens were approximately released to the market), please see our full reviews index.

(Measurements in ms)   Total Display Lag (SMTT 2) 3.25 Pixel Response Time Element 2.50 Estimated Signal Processing Lag 0.75 Lag Classification 1

Class 1

We have provided a comparison above against other models we have tested to give an indication between screens. The screens tested are split into two measurements which are based on our overall display lag tests (using SMTT) and half the average G2G response time, as measured by the oscilloscope. The response time is split from the overall display lag and shown on the graph as the green bar. From there, the signal processing (red bar) can be provided as a good estimation.

The screen showed a total lag of only 3.25ms. Approximately 2.5ms of that can be accounted for by pixel response times, leaving an estimated signal processing lag of only 0.75ms. This is basically nothing and means the screen should be fine for all levels of gaming. Other G-sync screens to date have shown similar very low levels of lag which is pleasing. This remains consistent at all refresh rates, and also when using ULMB.

Movies and Video

The following summarises the screens performance in video applications:

• 27" screen size makes it a reasonable option for an all-in-one multimedia screen, much smaller than LCD TV's and many larger format desktop monitors which are now emerging.

• 16:9 aspect ratio is well suited to videos and movies, leaving you with smaller/no borders on DVD's and wide screen content at the top and bottom than on a 16:10 aspect display.

• 2560 x 1440 resolution can support full 1080 HD resolution content.

• Digital DisplayPort interfaces support HDCP for any encrypted and protected content

• DisplayPort and HDMI connections available which is an improvement over older G-sync screens. The addition of HDMI is certainly welcome for connecting external devices and Blu-ray players.

• Cables provided in the box for DisplayPort and HDMI.

• Light AG coating provides clear images with no major graininess, and without the unwanted reflections of a glossy solution.

• Wide brightness range adjustment possible from the display, including high maximum luminance of ~331 cd/m² and a good minimum luminance of 56 cd/m². This should afford you very good control for different lighting conditions. Contrast ratio remains stable across the adjustment range as well and is excellent for an IPS-type panel. Brightness regulation is controlled without the need for PWM and so is flicker free at all settings which is pleasing.

• Black depth and contrast ratio are very good for an IPS-type panel at 989:1 after calibration. Detail in darker scenes should not be lost as a result.

• There is a specific 'cinema' preset mode available for movies or video in the OSD which is a bit cooler and more blue than our calibrated custom mode. You can customise it how you want which might be handy if you want to boost brightness for example for movies.

• Very good pixel responsiveness which can handle fast moving scenes in movies without issue. No overshoot issues when sticking to the 'normal' response time mode which is great news.

• Although it has 120Hz+ refresh rate support it does not support NVIDIA 3D Vision.

• Wide viewing angles from IPS panel technology meaning several people could view the screen at once comfortable and from a whole host of different angles. White glow from an angle on black content may be problematic to some users and is common for IPS panel technology.

• No real backlight leakage on our sample which is good.

• Wide range of ergonomic adjustments available from the stand, allowing you to adjust the screen to suit varying viewing positions.

• 2x 2W integrated stereo speakers offered on this model and an audio out connection.

• No hardware aspect ratio options on this screen, but graphics card can handle the scaling if using a PC. For external devices the native 16:9 format should mean most things aren't too much of an issue anyway.

• Picture By Picture (PbP) or Picture In Picture (PiP) are not available on this model.
  
   

Conclusion

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We really did like the PG279Q and we've now found our new reference gaming screen! The gaming performance was excellent, and second to none at the moment. Very fast response times for an IPS panel, 144Hz native refresh rate support, no lag, NVIDIA G-sync capability, ULMB blur reduction mode and a few nice gaming extras all add up to an excellent gaming offering. The overclockable refresh rate is little more than a marketing gimmick in our opinion, only because you already have a very high native refresh rate anyway and the bump isn't significant, let alone easy to power from your system. Had it been a boost from 60Hz to 165Hz we would have been more impressed at the change no doubt, but here it wasn't really necessary. On top of the gaming performance you have a very good default setup, strong contrast ratio, flicker free backlight and a quality build and design. The price point is of course high, but you are paying for a quality product here with some top notch performance.

We loved the PG278Q TN Film model when we tested it about 15 months ago but we do feel that the new PG279Q has the edge. Asus have moved to G-sync v2 so you've now got an additional HDMI input available. The IPS panel technology offers much better all-round performance so the screen is no longer limited to almost exclusively a gaming screen, but can be used very well for other tasks. The AG coating is lighter and less grainy, there's no overshoot evident at all on pixel transitions and the design has been improved a little with the thin bezel design. The TN Film PG278Q still has a place though in the market and might actually be preferred for some. It's about £150 cheaper than the new model and if you don't need the extra HDMI input and don't really need to use the screen for other uses beyond gaming it would still be an excellent choice. The TN Film panel might feel a little more fluid in use, but we preferred the balance here on the PG279Q without overshoot and still very good motion clarity. There's less glow on dark content from the TN Film model, which is perhaps the main weakness now of IPS technology. If manufacturers were to combine an IPS panel like this with a polarizer film to reduce that glow, it would be very welcome!

All in all it's an excellent screen and our number 1 choice right now for gaming. Get it while it's available as it's going to be a popular seller!