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Introduction

Gaming screens are certainly a big focus in the monitor market at the moment, spurred on by the arrival of new variable refresh rate technologies from NVIDIA (G-sync) and AMD (FreeSync). Over the last year we've seen fast TN Film gaming screens released with new 27" 2560 x 1440 panels. The Asus ROG Swift PG278Q and BenQ XL2730Z spring to mind as two excellent gaming screens built around this resolution, and combining it with variable refresh rate support. As well as developments in the TN Film gaming space we've also finally seen the release of high refresh rate IPS-type panels, in the form of models like the Acer XB270HU and Asus MG279Q - again with G-sync and FreeSync respectively. These have brought about some positive changes in the gaming space, finally allowing users to experience the benefits of IPS technology from a gaming display.

Also within the last year we've seen a steady increase in new ultra-wide screens offering 21:9 aspect ratios and some large screen sizes up to 34". Normal flat models like the LG 34UM95 were followed by a new breed of curved 34" screens like the Dell U3415W for instance. The ultra-wide screens have attracted a lot of interest from users as a good substitute for dual-screen operation, while also offering a very interesting possibility for multimedia and gaming thanks to their format and high 3440 x 1440 resolutions. Curved screens provide some immersion improvements (in our opinion) and feel a little more comfortable than flat models given their size and width.

A few manufacturers are now starting to invest in 34" screens which are specifically being targeted at gamers. The first to be released was the Acer Predator XR341CK, a 34" curved screen built around an IPS panel and supporting AMD FreeSync variable refresh rate technology and a maximum refresh rate boosted to 75Hz. We tested that a few months ago although it's still to be released in the UK at the time of writing this. We now have their G-sync equivalent with us for a full review, which is called the Predator X34. Some aspects of the design have been changed, and the refresh rate has even been boosted from the 75Hz offered on the XR341CK, to a reported 100Hz maximum. This is an "overclocked" refresh rate function which we will investigate during the course of this review. The X34 supports NVIDIA G-sync instead of AMD FreeSync, and so the retail price is a little higher than the XR341CK because of the additional G-sync module which is built in to the monitor. There is sadly no ULMB mode or 3D vision support on this model, but G-sync V II has allowed Acer to add an HDMI input at least where older G-sync screens were limited to DisplayPort only.

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Specifications and Features

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

The Predator X34 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 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. Unlike the FreeSync XR341CK model, this X34 does not feature PiP or PbP options due to the limited video interfaces.

Above: Acer Predator X34 boxed up

The screen has an external power supply brick which comes packaged along with the power cable you need. There are also 4x USB 3.0 ports, located on the back of the screen next to the video and power connections. Two have charging capabilities as well. There are also some 2x 7W DTS sound 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 underside edge of the screen. Click for larger version

Some of the quick launch menus are shown above, for OD mode and volume control. The input option just switches between DP and HDMI without popping up any menu.

Entering the main menu provides you with a wealth of options to play with. The menu is split down the left hand side into 5 sections, with options available in each shown on the right. At the bottom the icons tell you what each button will now do within the menu. There is also access to the 5 preset modes at the bottom via the green 'e' icon. They are basically just a series of 5 preset modes mostly down to different brightness settings. If you change anything yourself in the OSD then it reverts you to the 'user' mode automatically so you can't really customise the modes how you want unfortunately.

The first section in the main OSD menu is the 'picture' menu with options for the eColor management preset modes, brightness and contrast. The low blue light mode and dynamic contrast ratio (ACM) are also provided here if you want to use them.

The eColor preset mode menu is shown above for reference, with 5 modes available if you want.

The second section is the 'color' menu contains options for the gamma and colour temperature modes as well as adjustments for the RGB levels for calibration.

The third 'OSD' section has a few options relating to the menu itself. You can also access a couple of gaming options to display the refresh rate currently running in the top right hand corner (maybe handy when using G-sync) and also an 'aim point' for shooting games.

The 'setting' section has quite a few options in it. You can control the OD overdrive setting here and the overclocking feature. There is also access to the ambient light feature which we looked at in the previous section. Also included are options including the aspect ratio modes.

The final section contains a bit of info about the current settings of the screen.

All in all the menu had a lot of options to play with and the software looked nice and felt modern. It was a bit confusing to navigate sometimes and not that intuitive, having to drill in to different levels and then using lots of arrows back and forth. You sometimes find yourself having to go through many button presses to get to an option you want.

Power Consumption

In terms of power consumption the manufacturer lists typical usage of 54.0W, 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 56.3W at the default 80% brightness setting. Once calibrated the screen reached 40.6W consumption, and in standby it used only 0.5W. We have plotted these results below compared with other screens we have tested. The calibrated consumption is very similar to the LG 34UM95 (42.0W) but a little more than the Acer XR341CK FreeSync model (30.7W) and Dell U3415W (32.1W):

Panel and Backlighting

Panel Part and Colour Depth

Like the XR341CK FreeSync model, the Predator X34 features an LG.Display LM340UW2-SSA1 AH-IPS panel which is capable of producing 1.074 billion colours. As we understand it the panel offers an 8-bit colour depth with additional Frame Rate Control (FRC) stage added to support 10-bit content. Keep in mind whether this is practically useable and whether you're ever going to truly use that colour depth. You need to have a full 10-bit end to end workflow to take advantage of it which is still quite expensive to achieve and rare in the market, certainly for your average user. This includes relevant applications and graphics cards as well, so to many people this 10-bit support might be irrelevant. The part is confirmed when dismantling the screen. Incidentally this is the same panel we saw used in the Dell U3415W display as well.

Screen Coating

The screen coating on the Predator X34 is a light anti-glare (AG) offering, the same as that featured on the XR341CK model as well. 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. 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 (as was the XR341CK).

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 294 cd/m² which was just shy of the specified maximum brightness of 300 cd/m² from the manufacturer. There was a decent 281 cd/m² adjustment range in total, and so at the minimum setting you could reach down to a very low luminance of 13 cd/m². This should be more than adequate for those wanting to work in darkened room conditions with low ambient light and the screen could reach even lower than the 41 cd/m² of the FreeSync XR341CK model. A setting of 33 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 basically a linear relationship as you can see.

The average contrast ratio of the screen was very good for an IPS-type panel with an average of 1009:1. This was mostly stable across the brightness adjustment range as shown above with some fluctuation at the lower brightness settings below 30.

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 an X-rite i1 Pro Spectrophotometer (not to be confused with the i1 Display Pro colorimeter) 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 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:

Acer Predator X34 - Default Settings

 

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

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, mostly in blue and green shades but not by anything significant. Default gamma was recorded at 2.3 average, leaving it with a small 3% deviance from the target which was good. The screen has 4 gamma modes available in the OSD and by default it was set to the 2.2 gamma level. We also tested the other gamma modes for completeness and found the 1.9 mode returned a gamma average of 1.9 as intended, the 2.5 mode delivered a 2.5 gamma average as intended, and the 'gaming' gamma mode delivered an average gamma of 2.8. These gamma preset modes were reliable which was pleasing. We will stick with the 2.2 mode for our setup and calibration process as it's very close to the desired 2.2 level we aim for.

White point was measured at 6178k being slightly too warm from the target of 6500k but with a low 5% deviance. The screen was set in the default 'warm' colour temp mode incidentally. We again tested the other modes which returned the following colour temperature results:

Colour Temperature Modes

The white point was probably best at the default 'warm' mode out of the box, and closest to our target of 6500k. The user mode is identical but does give you access to the RGB channels to calibrate the screen yourself.  We will provide some recommended OSD setting adjustments in the following section to achieve a more accurate white point and default setup, even for those without a calibration tool available so you can try that too. Note that the low blue light mode also has another setting in the menu for levels of blue light reduction, defaulting to 70% when you enter that mode. There's also options for 50, 60 and 80% available.

Luminance was recorded at a very bright 246 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 0.24 cd/m² at this default brightness setting, giving us a very good static contrast ratio (for an IPS-type panel) of 1030:1. Colour accuracy was also good out of the box with a default dE average of 1.9, and a maximum of only 4.2. Testing the screen with colour gradients (after V2 firmware fix, see below) revealed smooth gradients with 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.

Acer Predator X34 - Optimum OSD settings

By changing any of the controls in the OSD you automatically move to the 'user' eColor preset mode anyway. We stuck with the default 2.2 gamma mode as it was closest to our 2.2 gamma target. We also changed to the 'user' colour temp mode which allows us to change the RGB levels individually. By making the basic changes to the OSD menu as listed above we were able to improve the default setup a little. We now had a slightly more accurate gamma, being measured at 2.2 average with a minor 1% deviance. White point was very close to our target with only a 1% deviance now, and the reduction in the brightness control delivered a more comfortable luminance, all the while maintaining a strong contrast ratio. The colour accuracy had also improved slightly, with 1.7 dE average now. Proper calibration as in the following section should help achieve even more accurate results.

Calibration

We used the X-rite i1 Pro 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.

Acer Predator X34 - 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 3% deviance we'd seen out of the box and leaving a minor 1% deviance. 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 6553k (1% deviance). Luminance had been improved thanks to the adjustment to the brightness control and was now being measured at 121 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 1033:1. Colour accuracy of the resulting profile was very good on the most part, with dE average of 0.6. However there seemed to be an issue with some shades, most notably yellow, where dE maximum reached up to 2.7. We tried to re-calibrate the screen several times, including in the 'warm' colour temp mode instead of 'user', but the same problem remained. Testing the screen with colour gradients (after V2 firmware fix, see above) revealed smooth gradients with some minor gradation evident in darker tones as you see from most screens.
 

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 and 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. That helps improve  the white point so it's easy to sort that if you want to.

The display was strong when it came to black depth and contrast ratio for an IPS-type panel. With a calibrated contrast ratio of 1033:1 it was comparable to some of the better screens using this kind of panel technology. It was not quite as high as the recently tested Dell U2515H (1138:1) which holds the record for an IPS contrast ratio. The XR341CK was ever so slightly higher too at 1072:1.  It was also very similar to the Dell U3415W (1091:1) as you might expect given they use the exact same panel. Of course none of these IPS screens can compete with VA panel types which can reach over 2000:1 easily like the 32" BenQ BL3200PT, and even close to 5000:1 in the case of the 24" Eizo FG2421 and 40" Philips BDM4065UC.

Viewing Angles

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

Viewing angles of the X34 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. 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. For a gaming screen, 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..

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. If you view dark content from a normal head-on viewing position, you can actually see this glow as your eyes look towards the edges of the screen. Because of the sheer horizontal size of this 34" panel, the glow towards the edges is more obvious than on small screens, where there isn't such a long distance from your central position to the edges. 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 extreme angle from your eye position to the screen edges. The glow effect was a little less than on flat 34" ultra-wide screens as the curved nature created a smaller angle between your eyes and the edges of the screen.

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" screen like this there are very wide fields of view and so you will notice it when sat up close to the screen and viewing 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.

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 36 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 seemed to be darker towards the top two corners where it dropped down by a maximum of 29% to 93 d/m². The central and lower middle portions of the screen were within a smaller variation from the centrally calibrated point though, but in a couple of places the luminance did jump up a bit to 124 d/m² maximum. Two thirds of the screen was within a 10% deviance from 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 and a bit of backlight bleed detected in the corners, most noticeably on the left hand side in the upper corner. It was not too bad though in normal use, but you could see it with the naked eye if viewing dark content in a dark room. Nevertheless it should not present any major problems in regular use.

General and Office Applications

One of the key selling points of ultra-wide screens like the this is it's high resolution and large screen size. The 3440 x 1440 display offers a sharp but comfortable picture. Its pixel area is about 1.8 times larger than an Ultra-Wide Full HD 21:9 monitor, and about 2.4 times larger than a Full HD 16:9 monitor. It provides an efficient environment in using Microsoft Office programs showing 47 columns and 63 rows in excel. Thankfully the high resolution is of a very comfortable size on the 34" panel, with a 0.2325mm pixel pitch is is very comparable to a 27" 2560 x 1440 monitor (0.2331mm). This means you are basically getting a wider desktop to work with, with a similar font size to a 27" model, and maintaining the same vertical resolution as well. If you're coming from a lower resolution / larger pixel pitch you may still find the fonts look quite small to start with, but like the 27" 1440p models out there you soon get used to it. Side by side multi-tasking on this screen is excellent and you really do have a nice wide area to work with. We liked the curved format of the display actually for day to day office work. It just felt a bit more comfortable than a flat screen on a model as wide as this, bringing the corners a bit nearer to you. You didn't really notice the curve in normal use but we liked the feel. Probably down to user taste, so if in doubt try and see one in person.

The light AG coating of the IPS panel doesn't produce any graininess to the image like some aggressive AG solutions can and so white office backgrounds look clean and clear. The wide viewing angles of the IPS panel technology provide stable images from different angles, meaning you can use the screen if you want for colour critical work, photos etc. It might be orientated at gamers, but it's IPS panel can deliver strong performance in other areas as well making it a good all-rounder. This panel technology still offers the widest viewing angles and so is well-suited to colour work. Some contrast shifts and IPS-glow may be evident because of the very wide size of the display, as you glance towards the edges from a centrally aligned position. That's hard to avoid on such a large desktop monitor from close up, even with IPS technology. The default setup of the screen was pretty good, and easy to tweak through the OSD to get an even better performance. We were also pleased with the strong 1033:1 contrast ratio (after calibration) as well.

The brightness range of the screen was also very good, with the ability to offer a luminance between 294 and 13 cd/m². This should mean the screen is perfectly useable in a wide variety of ambient light conditions, including darkened rooms. A setting of ~33 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 some feint audible noise whistling noise from the screen if you listened very closely, but not to the level we'd experienced on the XR341CK. This didn't seem to be related to refresh rate as some people have reported coil whine on their samples. The screen also remains fairly cool even during prolonged use. There is no specific preset mode for office work or reading so you will have to set the user mode how you want. If you need different settings for gaming you can save up to 3 user defined gaming modes as well which is very handy. Even with the use of G-sync v II, the screen is limited when it comes to connectivity options with only DP and HDMI available. Picture in Picture and Picture by Picture options are not provided on the X34, only on the XR341CK model.

The screen offers 4x USB 3.0 ports which can be useful and it was nice to keep this up to date with the modern version. Two also offer charging support 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 reasonable range of ergonomic adjustments available from the stand allowing you to obtain a comfortable position for a wide variety of angles. They were mostly stiff though so you might not want to move it around too often. We did miss swivel a bit though. The VESA mounting support may also be useful to some people as well for more flexibility.

 
Above: photo of text at 3440 x 1440 (top) and 2560 x 1080  (bottom)

The screen is designed to run at its native resolution of 3440 x 1440 and at a 60Hz 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 2560 x 1080 resolution to see how the screen handles the interpolation of the resolution, while maintaining the same aspect ratio of 21:9. 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

Both new Acer 34" ultra-wide screens are gamer-orientated, pairing an ultra-wide format curved display with a couple of gaming enhancements to deliver an interesting option for gamers. Firstly we should consider the format of the screen, with the 34" area offering a nice immersive experience and the wide 21:9 aspect proving popular for many gamers since it was introduced. It's nice also that the screen offers the full 3440 x 1440 resolution currently available on models this size, as opposed to the more limited 2560 x 1080 some 34" models have. The slight curve also adds to immersion feeling in games and we prefer it to flat 34" ultra-wide models.

At the moment the 34" monitor space is a little limited by the panels being manufactured. At the moment only LG.Display and Samsung seem to be investing in this format, with nothing reported in the roadmaps for other main manufacturers like AU Optronics or Innolux. There's really only the choice for display manufacturers between LG.Display's IPS, and Samsung SVA panels. That's not necessarily a bad thing as IPS is always very popular with buyers and using an IPS panel like Acer have here, does allow them to offer a screen suitable for a wide range of uses, not just exclusively for gaming. There are no TN Film panels in this size and format at the moment so the IPS option is about as good as you can get at the moment for gaming needs. Unfortunately, IPS is somewhat limited in what it can offer. This isn't a fault of Acer's, they are only working with what panels they have available to them and making the most of them. IPS technology (and Samsung SVA for that matter) is still fairly limited when it comes to pixel response times. It can't compete with the speed of TN Film panels, and as yet LG.Display haven't found a way to drive response times lower like AU Optronics have with their recent high refresh rate AHVA (IPS-type) panels in the 27" space. Still, people have been using IPS for many years for gaming so there's no reason to think that a screen like this couldn't be used as long as the response times are handled right. We will look at that in the next section. Sure, they won't be quite as fast as TN Film panels, but they are still fine for many users. The availability of TN Film panels in this format would have given Acer more choice perhaps, and the ability to offer an even better gaming experience. Although we expect people would only then moan about the restrictions of TN Film for other uses.

This leads us on to refresh rate. Again Acer are limited here by what is available panel-wise. LG.Display have yet to release any native high refresh rate (144Hz) IPS panel in any size. They have a 27" 1080p panel expected in Q3 at some point but that's their first venture into that space. Response times are likely to be the limiting factor in their quest, as they need to be able to reliably drive them under 6.94ms average (without loads of overshoot) to make 144Hz viable. We will see what they manage when they finally release a high refresh panel later in the year - assuming a display manufacturer picks it up. That aside, an even bigger problem is that the 3440 x 1440 resolution offered on a screen this size is too high to run at 144Hz with current DisplayPort standards. We would need to see DisplayPort 1.3 for that kind of bandwidth to be viable. All in all, it's likely to be a fair amount of time before we see a 144Hz native 3440 x 1440 screen sadly. In the mean time, Acer have done what they can with the available panel, within the confines of what it will support from a refresh rate point of view.

Boosted Refresh Rates

On the XR341CK model we tested before, the refresh rate had been bumped up from the normal 60Hz to 75Hz; at least when using an AMD graphics card. We found the 75Hz stable without frame dropping on an AMD system, giving a small but fairly decent 25% increase in maximum refresh rate from the panel. From NVIDIA graphics cards we found frames were dropped when pushing the refresh rate above 60Hz. We've heard some other user reports of similar things from NVIDIA systems on the XR341CK. For AMD users, the slight increase was welcome as it had been paired with AMD's FreeSync technology and so this higher refresh rate allows a wider dynamic refresh rate range to be used. 30 to 75Hz is available on the XR341CK which is a decent range, and to be honest most of the FreeSync benefits would be realised within that range anyway. If you've got a powerful enough graphics card to output >75fps at 3440 x 1440 res then you can just set vsync to off for frequencies outside of the supported range and live with a bit of tearing, while delivering higher frame rates to the display.

The Predator X34 is a little more adventurous though and we're excited to see how it performs. The panel being used is still a native 60Hz panel, but Acer have built in an "overclocking" feature which allows the user to reach up to 100Hz refresh rate maximum. Some people have moaned that the user manual states that this is at the owners risk, which seems to go against the advertised spec and feature list. The documentation also states it is "up to 100Hz", so it appears to not be a guaranteed refresh rate, only what you might be able to reach. We have asked Acer for clarification on how using this feature might affect a users warranty, if at all, and if there are any guidelines on what users should expect given the "up to" message. We will update this section of the review when we have more information.

This higher refresh rate support has been paired with an NVIDIA G-sync module, offering G-sync variable refresh rate support between 30 and 100Hz. The overclocking facility of the screen seems to be related to the presence of a G-sync module, or perhaps more precisely down to the absence of a built-in scaler. Future overclockable screens announced so far (e.g. Asus ROG Swift PG279Q @ 165Hz and Acer Predator Z35 @ 200Hz) are also G-sync capable so that seems to be the key here.

The screen is recognised by Windows as a 60Hz panel by default, and that's the maximum you can select when you first connect the screen. The support for higher refresh rates is enabled via the OSD menu using the "over clock" feature as shown above. You enable this and the monitor reboots itself. Once that's done, in Windows you then have further options available to select for refresh rates up to 100Hz. We will test these higher refresh rates during the following sections of this review, checking if any frames are dropped and if there appear to be any side effects. We will also test these from both an NVIDIA and an AMD graphics card for comparison.

Additional Gaming Features - Where is ULMB?

Sadly one thing which is missing from the X34 is a Blur Reduction mode. We were expecting ULMB to be available as part of the G-sync module, but it has not been provided here. Presumably that has something to do with the refresh rate range here, as providing ULMB at lower refresh rates <85Hz is generally considered too flickery, and since the higher refresh rates are not guaranteed here it was probably too much to ask for. NVIDIA 3D Vision is also not supported, as that needs refresh rates of 120Hz minimum to function correctly (60Hz per eye in active shutter mode).

To make the most of this screen you will want to have a suitable NVIDIA graphics card which supports G-sync. That will allow you to use one of the most interesting new features of this screen, the G-sync support. Since the screen needs an additional G-sync module to make this function work, there is an added cost compared to the XR341CK FreeSync model. As such, this premium is unlikely to make the screen attractive to AMD users, who would probably be better off with the XR341CK where FreeSync is supported and the retail cost quite a bit lower.

Responsiveness and Gaming

The Predator X34 is rated by Acer 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 Mode' (overdrive) option. The part being used is the LG.Display AH-IPS LM340UW2-SSA1 panel, the exact same panel as already used in the Dell U3415W display. 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 Predator X34 comes with a user control for the overdrive impulse available within the OSD menu in the 'setting' section, as well as via one of the quick launch options shown above. There are 3 options available here under the OD Mode setting. First of all we carried out a fairly small set of measurements in all 3 of the OD Mode settings. These, along with various motion tests allowed us to quickly identify which was the optimum overdrive setting for this screen. Note that for now we have stuck with the native 60Hz refresh rate of the panel. These tests are just designed to help us identify the optimal OD setting, and we will check the response times again when we come to overclock the refresh rate. We tested the screen from an NVIDIA and AMD system which both delivered comparable results here.

Firstly we tested the response times with OD set to off, effectively turning off the overdrive impulse. The average response time was measured at 12.9ms G2G average which was actually not that slow, but certainly not optimum for this technology. Rise times were 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 9.0ms now which was better, and only a little slower than the best case 60Hz IPS panels around, which can reach down to around 8.6ms G2G without introducing noticeable amounts of overshoot. So 9ms G2G was not a bad performance really from a current 60Hz IPS panel. The XR341CK display had reached down to 8.7ms G2G in this 'Normal' OD mode, albeit from a slightly faster 75Hz refresh rate from an AMD system so it was still very close to that. There was some minor overshoot on a couple of transitions but this shouldn't be a problem in actual use.

Finally we tested the 'Extreme' OD mode. There was an improvement in measured response times down to 6.9ms G2G average. However, it was at the cost of some very high overshoot, which was obvious and distracting during actual use. Stick with the 'normal' OD mode.

We can also make some visual comparisons of the three OD modes using the moving images of the PixPerAn tool. The above photos were captured in each of the OD modes. With OD off, there was a fairly obvious blurring to the moving image, something that was largely eliminated when switching up to the 'normal' mode. Blurring was reduced a lot and the image became sharper. There were no signs of noticeable overshoot either in this mode in these tests which was pleasing. The 'extreme' mode pushed things too far, and dark and pale overshoot trails were introduced as you can see. Stick with the normal mode for optimal performance.

Refresh Rate

One of the most interesting features of the X34 is the overclockable refresh rate. The panel itself is designed to run at 60Hz by LG.Display and that's the native refresh rate you will be able to select in Windows when you first connect the screen. However, there is a specific feature available in the OSD menu in the 'setting' section for "over clock". This allows you to enable the higher refresh rate support. The manual states that this is "at the end users risk" which some people have complained about given the advertising of the screen as supported 100Hz. The messaging on most of Acer's documentation and websites also says that it is "up to" 100Hz which implies results may vary perhaps. We have asked Acer for clarity on whether using this feature in any way affects the warranty of support for the screen and will update this review when we have more information. We've also asked if there are any guidelines on what users should expect from their overclock and if there are graphics card/system expectations at all. For now, you can probably take some solace in our findings below.

Once you enable the overclocking feature you can choose then the max refresh rate which you want to be available in Windows, from 75Hz in steps of 5 up to 100Hz maximum. You then just have to use the "apply and reboot" option which restarts the monitor.

     
Above: Windows refresh rate settings at default, and then 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. 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.

We had no issues with running at any of these refresh rates from our tests system, using an NVIDIA GTX 750 graphics card. All of them worked fine in Windows with no visible artefacts or flickering. Some users have reported some coil whine from the screen when using overclocked refresh rates on the X34 but we heard nothing different at any refresh rate. There is a very feint electric whistle from the screen if you listen really closely to it (we mean very close!) but that is there even at 60Hz so it's nothing to do with the refresh rate overclocking. If you have a really obvious whine from the screen which is an issue for you, we would suggest contacting Acer for an RMA as that doesn't seem to be an issue affecting every sample. Certainly ours was fine.

Most importantly, 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 100Hz refresh rate. This overclocking seemed to work very well, at least from our test system and we were impressed. We expected that using an AMD graphics card might be different (an AMD Club 3D Radeon R9 290 series) but we were very pleasantly surprised to see that the results were the same on that system. No frames were dropped even at the maximum 100Hz, and we had no issues at all overclocking the screen to various refresh rates all the way up to the maximum.

60Hz Refresh Rate

100Hz Refresh Rate

On another interesting note, we found that the response times were improved when running at a higher refresh rate. We've seen this form some other screens as well where response times are somewhat influenced by the active refresh rate. Here, we saw a decent improvement in response times when you compare them at 60Hz and at 100Hz. In both cases we were using the optimal OD normal setting by the way. Pixel transitions improved down to 7.5ms G2G with the 100Hz refresh rate, and the small amount of overshoot we saw before was also eliminated. A pleasing result, and some decent response times from an IPS-type panel. With an average G2G of 7.5ms, it is suitably low enough to support the 100 fps frame rate available here, since the screen needs to refresh every 10ms. When response times are slower than the refresh frequency a lot of blurring is introduced, but that's not a problem here on the Predator X34. The G-sync operating range is 30 - 100Hz maximum, depending on if you've used the overclocking feature which gives you a nice wide range. Given the high resolution here, the G-sync support combined with a wide dynamic range should provide a very pleasing gaming experience. We ran some G-sync tests which looked smooth and performed well.

More Detailed Measurements
OD Normal, 100Hz 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 overclocked refresh rate of 100Hz since that had been stable on our test system and delivered the optimal response time performance.

The average G2G response time was more accurately measured at 7.9ms which was very good overall for an IPS-type panel. Transitions were a little slower on rise times (changes from dark to light) but not by anything significant. One transition (0-100) seemed to be a little slower than everything else, measured at 15ms, where the overdrive impulse was perhaps not quite as well tuned. Overall the response times were faster than the best 60Hz IPS panels available at the moment, which can reach down to about 8.6ms G2G average without overshoot. Here, the 100Hz overclocked refresh rate helped push them a little lower which was pleasing.

There was no overshoot at all on any transition as long as you were using the maximum refresh rate. Having tested OD normal at 60Hz there was some very minor overshoot detected, but nothing you should notice in normal use anyway.
 

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 60Hz refresh rate the response times (9.0ms G2G) were only a little slower than some of the best 60Hz IPS-type panels available, which can reach down to ~8.6ms G2G while remaining free of overshoot. When you push the refresh rate up to 100Hz (which was reliable from our NVIDIA and AMD systems without frame dropping) the response time are improved nicely, down to 7.9ms G2G which is impressive. There is also no overshoot at all at this refresh rate as long as you stick to the 'normal' OD mode. This left the screen as being slightly faster than the XR341CK which could reach 8.7ms G2G at its maximum 75Hz refresh rate. It was also quite a bit faster than the other 34" widescreen displays we've tested like the Dell U3415W (10.6ms G2G) and LG 34UM95 (9.5ms G2G). Very pleasing performance really when it comes to pixel response times.

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.

34" 4ms G2G LG.Display AH-IPS @ 100Hz (OD = Normal)

In practice the Acer Predator X34 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 100Hz 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.

34" 4ms G2G LG.Display AH-IPS @ 100Hz (OD = Normal)

34" 4ms G2G LG.Display AH-IPS @ 75Hz (OD = Normal)

34" 8ms G2G LG.Display AH-IPS (Response Time = Normal)

34" 5ms G2G LG.Display AH-IPS (Response Time = Middle)

The above images show a comparison with the Acer XR341CK model (FreeSync version) along with the other two other 34" ultra-wide screens we've tested. The X34 with its faster response times and higher refresh rate was a bit better than the XR341CK version with a less noticeable blurring. The Dell U3415W featured the exact same panel as the Acer screens but was a little slower than both in practice we felt. Our oscilloscope measurements also confirmed slower response times on the Dell, and some low levels of overshoot which the Acer did not have. The LG was pretty similar to them both as well although slightly slower again than the Acer. The X34 definitely has the edge here, largely thanks to its overclocked 100Hz refresh rate.
 

34" 4ms G2G LG.Display AH-IPS @ 100Hz (OD = Normal)

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)

23.5" 4ms G2G Sharp MVA + 120Hz

We've also included a comparison above against some other very fast 120Hz+ compatible screens we have tested. The screens shown here are all aimed primarily at gamers and have various features and extras which make them more suitable overall for gaming. Firstly there is a comparison against the excellent Acer XB270HU with very fast response times (5.5ms G2G, no overshoot), native 144Hz refresh rate and also NVIDIA G-sync and Ultra Low Motion Blur (ULMB) support. It's currently our bench-mark for IPS panel gaming - well, actually our current favourite gaming screen of any type! It has the edge over the X34 when it comes to refresh rate support and image smoothness, also thanks to the fact it is a native 144Hz support and with no need to overclock the screen (which may or may not be reliable on other systems with the X34).

Then there's the very popular Asus ROG Swift PG278Q with its 144Hz refresh rate and fast response time TN Film panel. This showed very fast pixel response times (2.9ms G2G), with moderate levels of overshoot, but smooth movement thanks to its increased refresh rate. You are able to reduce the motion blur even more through the use of the ULMB strobed backlight as well if you need to and again this model also supports NVIDIA's G-sync technology.

Then there is a comparison against the BenQ XL2730Z with another very fast TN Film panel and 144Hz refresh rate. This showed very low levels of motion blur (3.4ms G2G), but some dark overshoot was introduced as a side-effect as you can see. This screen also includes a native Blur Reduction mode to help eliminate further perceived motion blur and works well, along with AMD FreeSync support.

Lastly there is the MVA based Eizo FG2421 screen with a fast response time (especially for the panel technology being used) and 120Hz refresh rate support. There is also an additional 'Turbo 240' motion blur reduction mode which really helps reduce the perceived motion blur in practice.

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, particularly when using the overclocked 100Hz refresh rate.

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. 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. Unfortunately there is no Blur Reduction (ULMB) mode available from this screen so you are not able to reduce perceived motion blur further using a strobe backlight.

~
Note: optimal overdrive settings used on each screen

We can also compare the pursuit camera tests at 60Hz and 100Hz compared with a couple of very fast and very popular gaming screens above. The X34 performs very well in these tests and you can see the benefits on blurring by using the higher refresh rates. So not only are you getting improvements in frame rate, fluidity and response times - you're getting reductions in perceived motion blur. It should be noted that the Acer XB270HU and Asus ROG Swift PG278Q can both push past 100Hz and up to 144Hz refresh rate, helping to eliminate the blurring even more. Their added blur reducing ULMB modes really help improve image clarity on moving images when used as well. Check the reviews linked for both those screens for further information on that.

Additional Gaming Features

• Aspect Ratio Control - The X34 has 2 options listed in the menu for aspect ratio control through the OSD 'setting' section menu. There are options for aspect and 1:1 pixel mapping. However, these didn't seem to work when we tested them. If you run at anything other than the native resolution, the aspect ratio is maintained. e.g. a 1920 x 1080 resolution has black borders on the sides. However, the 1:1 pixel mapping didn't seem to do anything, the image always just filled as much of the screen as possible. With the aspect ratio at least being maintained it was not a problem though as that's the main thing.

• Preset Modes - There are 3 game modes which you can customise and save you like, which allows you to set the screen up for different applications. You can use these for other uses as well of course if you wanted to.
   

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) 9.20 Pixel Response Time Element 3.95 Estimated Signal Processing Lag 5.25 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 9.2ms. Approximately 3.95ms of that can be accounted for by pixel response times, leaving an estimated signal processing lag of only 5.25ms. 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.

Movies and Video

The following summarises the screens performance in video applications:

• 34" screen size makes it a good option for an all-in-one multimedia screen, and pushing towards the diagonal size of a lot of smaller end LCD TV's even.

• 21:9 aspect ratio is well suited to videos and particularly movies, leaving smaller borders on DVD's and wide screen content at the top and bottom. The ultra-wide aspect and size is well-suited to watching movies and really works well.

• 3440 x 1440 resolution can support full 1080 HD resolution content.

• Digital interfaces support HDCP for any encrypted and protected content

• HDMI and DisplayPort connections available. Nice to see HDMI connectivity included for modern DVD players, Blu-ray, consoles etc thanks to the use of G-sync v II here.

• Cables provided in the box for HDMI and DisplayPort.

• 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 294 cd/m² and a good minimum luminance of 13 cd/m². This should afford you very good control for different lighting conditions. Contrast ratio remains stable across most of that adjustment range as well and is excellent for an IPS-type panel at >1000:1. 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 1033:1 after calibration. Detail in darker scenes should not be lost as a result.

• There is a specific 'movie' eColor preset mode available for movies or video in the OSD which is basically just preset brightness level. You might be better setting up the screen to your liking and saving it then as one of the 3 user defined game modes.

• Very good pixel responsiveness which can handle fast moving scenes in movies without issue. No overshoot issues which is good news as well. Just stick to the 'Normal' OD setting for optimum performance.

• 100Hz refresh rate improves fluidity of moving images and reduces perceived blurring to a degree.

• 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 IPS glow from an angle may be an issue for some darker content.

• Some slight areas of backlight leakage but nothing major on our sample which is good. Some uniformity variations may be visible on darker movie scenes in darkened room conditions.

• Pretty good range range of ergonomic adjustments available from the stand, making it fairly easy to position the screen in different ways for viewing from different positions. They were stiff to move and the screen is heavy, so you won't want to move it around too often. The lack of side to side swivel was a bit of a shame though.

• Integrated 2x 7W DTS sound stereo speakers offered on this model, may be ok for the odd video clip but probably not for any movie viewing.

• There are options for hardware aspect ratio control, but they don't seem to function properly from our testing. They do at least maintain the source aspect ratio which is the main thing, so that should work fine for external devices which commonly operate in 16:9 format.

• Picture By Picture (PbP) and Picture In Picture (PiP) are not available on this model, unlike the XR341CK.
  
   

Conclusion

We know how excited people were to get a detailed review of this monitor as quickly as possible, so we decided to release this as a full review straight away. We worked overtime to bring you this quickly as well so if you appreciate the early access to the review and enjoy reading and like our work, we would welcome a donation to the site to help us continue to make quality and detailed reviews for you.

We were impressed by the Acer Predator X34 overall and thought it was a very good gaming screen. The main area of interest is obviously the overclocked 100Hz refresh rate. We know some people are up in arms about how this has been advertised, and the whole "at the users risk" statement in the OSD menu. At the end of the day we really doubt this will have any affect on user warranty (we are confirming with Acer) and if it works reliably, there doesn't need to be an issue. We suspect it's a case of Acer covering themselves given the native refresh rate support of the panel, and in case it doesn't quite reach 100Hz on every system. We were pleased to find it reached 100Hz reliably on both our NVIDIA and AMD systems, without frame dropping and without any observed side-effects. The boosted refresh rate lead to improved response times, which were very good for an IPS-type panel and without any overshoot evident as well. The refresh rate boost brought about improvements in image fluidity, frame rates and perceived motion blur and provides a really good range in which the added G-sync function can operate. The addition of G-sync is obviously really attractive to NVIDIA users and adaptive refresh rates are big plus of any screen now for gaming. The screen also benefited from very low lag making it a very strong option for gaming, especially considering the popular ultra-wide format and high resolution used here.

Default setup was good and the contract ratio was strong for an IPS panel. The use of a flicker free backlight and light AG coating is always positive as well. We liked the design of this X34 model and felt it looked a bit better than the XR341CK. The stand is somewhat limited and quite stiff to move but it looks pretty sleek still. We were also pleased that the latest G-sync module allowed Acer to provide an additional HDMI input. It's still more limited than FreeSync screens, but it's an improvement over the previously limited single DisplayPort connection.

There were a couple of areas of concern / disappointment. Firstly the banding issue on blue colour gradients was a clear problem with the initial firmware when we first tested the screen and something Acer had to address before stock was widely available. It is now fixed and confirmed working in our tests. See our relevant section of this review for up to date information on the new firmware and any affected regional stock. That was really the only problem with the screen as we found no issues with reported coil whine or artefacts/problems at high refresh rate. Our unit showed pretty good panel uniformity and no major backlight bleed. You do need to be prepared for the characteristic IPS glow, which should not be confused with backlight problems as we've discussed. We were a little disappointed ULMB is not included but that probably needs to be saved for native high refresh rate panels above 100Hz.

This really is a very good gaming screen. If you're after an ultra-wide with high resolution, G-sync support and a nice boosted 100Hz refresh rate this is definitely worth checking out.