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Introduction

We seem to have spent a good part of 2015 reviewing new gaming screens as they've emerged on the market, and we do intend to start looking at some more mainstream and generalist monitors in 2016 when we can. The reason for this has been such a big focus on gaming developments in the monitor market last year, with new innovations like variable refresh rate (G-sync and FreeSync) being launched, and big changes in refresh rates, blur reduction technologies and screen size. In July last year we reviewed Acer's 34" XR341CK monitor which boasted an overclocked IPS panel (75Hz max), FreeSync support and a 34" ultra-wide, curved screen. This was followed later in September by the G-sync-ready Predator X34 model of the same size and format, but with 100Hz overclocked refresh rate as well.

There's certainly been a push for bigger gaming screens last year, and an additional push to offer higher refresh rates as well. We now have Acer's new Predator Z35 monitor with us for review. This is a 35" ultra-wide screen with a curved VA panel. The refresh rate is natively 144Hz but this screen can even be overclocked up to a whopping 200Hz. It's been combined with NVIDIA G-sync capabilities and additionally their ULMB (Ultra Low Motion Blur) backlight system. Clearly it's designed with gamers in mind and offers some impressive specs and features which are bound to attract attention. We will have a look at how all these features perform during the course of this review.

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Specifications and Features

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

The Predator Z35 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.

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. One has charging capabilities as well. There are also some 2x 9W DTS sound integrated speakers, and also an audio-out port 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 '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. Acer have added a "dark boost" feature designed to boost the gamma in the darker tones which might be useful in some games.

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 47.0W, and 0.47W 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 66.5W at the default 80% brightness setting. Once calibrated the screen reached 42.0W 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 other larger format screens we've tested like the Acer Predator X34 and LG 34UM95 for instance.

Panel and Backlighting

Panel Part and Colour Depth

The Predator Z35 features an AU Optronics M350DVR01.0 AMVA (VA-type) panel which is capable of producing 16.7 million colours through an 8-bit colour depth. You can actually make out the panel label if you peer through the air vents on the back of the screen, which was handy as it saved us having to open the screen up.

Screen Coating

The screen coating on the Predator Z35 is actually a little more grainy than we expected. It's not quite as grainy as TN Film panels, which we would classify as having a moderate coating, but it's not quite as light and clear as modern IPS-type panels. Somewhere in the middle. 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 no cross-hatching patterns visible on the coating but given the relatively low resolution of a panel this size, you could pick out individual pixels if you moved very close to the screen. Not a problem from a sensible viewing position though.

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 359 cd/m² which was actually quite a lot higher than the specified maximum brightness of 300 cd/m² from the manufacturer. This bodes well as the brighter the backlight is, the brighter you can hope for when using the ULMB feature (tested later on). There was a decent 305 cd/m² adjustment range in total, and so at the minimum setting you could reach down to a low luminance of 54 cd/m². This should be adequate for those wanting to work in darkened room conditions with low ambient light. A setting of 18 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, with an average of 2909:1. Again, this surpassed the spec of 2000:1 which was very pleasing. We have not provided the usual contrast stability graph since rounding errors can come in to play at high contrast ratios like this.

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:

Acer Predator Z35 - 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 2 device.

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 most shades but not by anything significant. Default gamma was recorded at 2.4 average, leaving it with a small 8% deviance from the target which was not too bad. The screen has 2 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 1.8 mode returned a gamma average of 2.2 which was closer to your target (minor 2% deviance). We would recommend moving to the 1.8 gamma mode in the OSD for a slightly better default setup:

Default setup - 1.8 Gamma mode

White point was measured at 6147k 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. 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 338 cd/m² which is too high for prolonged general use, and even beyond the specified 300 cd/m² maximum. This is with the brightness control at only 80% as well. 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 0.11 cd/m² at this default brightness setting, giving us an excellent static contrast ratio of 3063:1, again beyond the 2000:1 spec. This gives you deep, dark blacks which surpass what is possible from IPS or TN Film screens. Colour accuracy was also good out of the box with a default dE average of 1.8 (once switched to the slightly better 1.8 gamma mode), and a maximum of only 4.0. Testing the screen with colour gradients revealed smooth gradients with some gradation evident in darker tones as you see from most screens. No banding issues visible thankfully.

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 Z35 - Calibrated Settings

   

All the OSD changes listed in the table above allowed us to obtain an optimum hardware starting point and setup before software level changes would be made at the graphics card level. When you enter the 'user' colour temp mode you can drill in to it one more step to access the RGB channel gain controls. 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 the minor 2% deviance we'd seen out of the box (gamma mode 1.8). The white point was now measured at 6513k after adjustments to the RGB channels. 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 very low black depth of 0.04 cd/m² and maintained an excellent static contrast ratio of 2813:1 thanks to the VA panel. Colour accuracy of the resulting profile was very good with dE average of 0.4. Testing the screen with colour gradients revealed mostly smooth gradients with some gradation evident in darker tones as you see from most screens and some minor banding introduced in darker shades due to the gamma corrections.

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 good overall. We'd recommend switching to the 1.8 gamma mode in the OSD which then produces a better setup with an accurate gamma curve, strong static contrast ratio and low dE. White point was slightly too warm but only by a minor 5% deviance and easy to correct through basic RGB adjustments in the OSD menu. With those few basic OSD settings you have a strong setup which should suit most users.

The display was very strong when it came to black depth and contrast ratio thanks to its VA panel. With a calibrated contrast ratio of 2813:1 it was comparable to some other VA panels in the market, in fact exceeding our expectations based on the 2000:1 spec. It wasn't quite as high as some other VA panels we've seen which can reach up to around 4000 - 5000:1 in some cases, but at 2813:1 it was still excellent and far surpassing anything possible with TN Film and IPS-type panels. This was certainly a strong point of the Z35's VA panel.

Viewing Angles

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

Viewing angles of the Z35 were a little disappointing to be honest. The image behaved more like older generation VA panels than some of the modern VA screens we've tested of late. From a side angle, the image became washed out and yellow in appearance as you can see. The same was visible from above and below. It reminded us of some older generation VA panels such as that used in the BenQ GW2750HM for instance. We had hoped for better, as we had seen improvements in VA viewing angles with more recent models like the BenQ GW2760HS and BenQ BL3200PT for instance. So here, despite it being a brand new panel from AU Optronics, it seems viewing angles have taken a bit of a step back. Perhaps there's been less focus on this area with the push for high refresh rate support and the new 35" curved format?

The viewing angles were still a bit better than TN Film matrices, commonly used in gaming displays. There was a less pronounced contrast shift vertically here. The colour tone and gamma shifts were more noticeable of course than IPS-type panels, including the 34" Acer Predator X34 as an example. Users should also be aware that the panel exhibits the off-centre contrast shift which is inherent to the VA pixel structure. When viewing a very dark grey font for example on a black background, the font almost disappears when viewed head on, but gets lighter as you move slightly to the side. This is an extreme case of course as this is a very dark grey tone we are testing with. Lighter greys and other colours will appear a little darker from head on than they will from a side angle, but you may well find you lose some detail as a result. This can be particularly problematic in dark images and where grey tone is important. It is this issue that has led to many graphics professionals and colour enthusiasts choosing IPS panels instead, and the manufacturers have been quick to incorporate this alternative panel technology in their screens. We would like to make a point that for many people this won't be an issue at all, and many may not even notice it. Remember, many people are perfectly happy with their TN Film panels and other VA based screens. Just something to be wary of if you are affected by this issue or are doing colour critical work.

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

We captured a photo of an all-black image as viewed from a side angle as shown above. This can help exhibit any glow you might see on different panel technologies. Here, on the Z35 the actual glow caused by the VA panel technology was quite low, with some pale areas picked up in the photo. This side-angle photo actually captures some of the uniformity issues we measured in the following section, and you can clearly see the darker and lighter areas of the screen. From a head on viewing position this is hard to see, but viewing the screen from a side angle accentuates it.

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 not very good from our sample. We measured two obviously darker regions of the screen on either side. The luminance dropped off quite a lot down to 89 d/m² in the most extreme cases. Only 36% of the screen remained within a 10% deviance of a centrally calibrated 120 cd/m² point which was disappointing. Results will vary from sample to sample of course, but the luminance uniformity was a bit of an issue on the sample we tested. It didn't really cause any obvious problems in general day to day uses to be honest.

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 once the screen had been calibrated to a sensible day to day 120 cd/m². A camera was used to capture the result from a distance of ~2m to limit any glow which might be caused by viewing angles. The camera showed there was some slight clouding and a bit of backlight bleed detected in the corners, but this was very hard to notice with the naked eye at a calibrated brightness level. If you view the screen from the side, you can pick out the areas of clouding more easily, as we saw in the previous section of the review. Day to day, from head-on we didn't see any noticeable issues with bleed.

General and Office Applications

One of the key selling points of ultra-wide screens like the this is normally the high resolution and large screen size. Despite the 35" screen size on the Z35, the resolution is actually a lot lower than one might like for office-type work. It's only 2560 x 1080 and so the display has a large pixel pitch of 0.320mm and large fonts as a result. Text looks big and less sharp than we are used to from common screens such as the wide range of 27" 2560 x 1440 we use day to day. Smaller 34" models like Acer's XR341CK and X34 are also able to offer up to 3440 x 1440 resolution and so provide a sharper, clearer image thanks to their smaller 0.233 mm pixel pitch; not to mention a much bigger desktop size to work with. So on the Z35, this lower resolution is a draw-back when it comes to general desktop and office type uses. We did get used to it after a little while, but the image just didn't look as clear as higher resolution panels. You could still do some split screen side by side working thanks to the 2560 horizontal resolution, but vertically it was a bit limited. If you compare the pixel pitch of 0.320mm on this model with other screens in the market, it's fairly comparable to some 27" models you can find with 1920 x 1080 resolution. A 28" screen at 1080p would be a closer comparison to how the text looks on the Z35. If office work is your main use, we would probably suggest looking for a screen with a higher resolution. This is purely aimed at gaming and we feel with the resolution being what it is, it should probably be used for gaming and multimedia as much as possible and not much else.

There is a reason for this lower resolution though. Firstly Acer are limited by available panels produced by the key panel manufacturers in the market. At the moment, the only 35" panels in production are from AU Optronics and they only manufacturer them at 2560 x 1080. This is linked to their native 144Hz refresh rate from the panel though, which would be beyond bandwidth limitations of existing DisplayPort 1.2 connections if the resolution was higher at 3440 x 1440. Not to mention the fact Acer have enabled an overclock up to 200Hz which pushes that bandwidth requirement even further. Perhaps with the arrival of DisplayPort 1.3 later this year we might start to see high refresh panels with higher resolutions as well. Added to this technical limitation is the potential market for a screen like this. It would take a very powerful system to reliably run a screen at 3440 x 1440 @ 200Hz, and so by limiting the resolution to 2560 x 1080 they make this more achievable for more users. In fact, in gaming you are less likely to notice the lower resolution than you might in desktop use and so it becomes less of an issue.

The fairly light AG coating of the VA panel doesn't produce any graininess to the image like some aggressive AG solutions can and so white office backgrounds look fairly clean and clear, perhaps not quite as clear as we had hoped. The viewing angles of the VA panel technology were not great sadly, and a step back from some other modern VA panels we've tested in fact. You will notice fairly obvious contrast and colour tone shifts if you move your line of sight around much of view the screen from an angle. Some contrast shifts 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. 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 ~2900:1 contrast ratio as well which is certainly a strength of the VA panel.

The brightness range of the screen was also very good, with the ability to offer a luminance between 354 and 18 cd/m². This should mean the screen is perfectly useable in a wide variety of ambient light conditions, including darkened rooms. A setting of ~18 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 no audible noise or whistling noise from the screen. 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.

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. One also offers charging support but all of them are located on the back of the display so are not easy-access really. Integrated 2x 9W 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 and the lack of VESA mounting support may also be off-putting to some people as well who wanted more flexibility.

Gaming Introduction

Several things make the Z35 stand out when it comes to gaming:

• Refresh Rate - the VA panel has a native refresh rate support from AU Optronics of 144Hz so right away you know that the panel should be able to achieve decent refresh rates without complications.
   

• Overclocking - Acer have then enabled an overclocking feature allowing you to overclock the screen up to 160, 180 or 200Hz maximum. This is quick and easy to achieve through the OSD menu. The reason for the "up to" 200Hz message is because you can customise the maximum refresh rate you want to select in the OSD, in 20Hz increments all the way up to 200Hz. We have been told that overclocking does not affect the Acer warranty, which carries standard warranty terms and is available via the Acer support website. We are told that once enabled in the OSD the monitor will report back to your operating system the supported refresh rates and it should not matter what graphics card vendor you are using. Based on this you should be able to get 200Hz in most cases it seems. Results may vary from system to system so you may have to limit yourself to 180Hz. Even without the overclocked refresh rate the native 144Hz is more than adequate and very fast anyway.
   

• NVIDIA G-sync - this higher refresh rate support has been paired with an NVIDIA G-sync module, offering G-sync variable refresh rate support between 30 and 144Hz, or up to the maximum overclocked refresh rate if you select that. 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. G-sync brings about obvious benefits when it comes to gaming and so is very welcome.
   

• ULMB Blur Reduction - this has been provided natively on this screen allowing users to operate a strobed backlight if they wish, for noticeable motion blur reduction benefits. Have a read of our full article about these technologies to understand the benefits in more detail. On the Z35, ULMB can be enabled at 85, 100 and 120Hz refresh rate settings (not 144Hz or above) but is not available when using G-sync.

The screen is recognised by Windows as a 144Hz 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 200Hz. 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.

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 two of the most interesting features of this screen, the G-sync support and the ULMB feature. Since the screen needs an additional G-sync module to make this function work, there is an added cost to production.

Responsiveness and Gaming

The Predator Z35 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 AU Optronics M350DVR01.0 AMVA (VA-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 Times and Refresh Rate
 

The Predator Z35 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, as we've seen on other recent Acer screens. 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. There are some further important considerations when it comes to refresh rate which we will look at as well.

OD Off

Firstly we tested the response times with OD set to off, effectively turning off the overdrive impulse. These results remained pretty consistent across all refresh rates with OD off. We know from some other screens that the G-sync modules often seem to dynamically impact the response times and overdrive impulse at different refresh rates and we expected the same thing from this screen. With OD off here, there was no overdrive impulse to control so the refresh rate made little difference to the actual pixel response times. It did however have a big impact on motion clarity and blurring which we will look at in a moment.

With OD off, the average response time was measured at between 17 and 16ms G2G average which was very slow really. There were some transitions which were extremely slow and problematic, for instance the 0-50 transition was a whopping 56.5ms! In fact only the changes to white (x > 255) and to black (x > 0) were fast at around 6 - 8ms, with mid-tone transitions being slow at around 14 - 24ms. There was no overshoot in this mode, but the response times were far too slow for gaming or fast moving content. VA type panels have never been that fast, and without overdrive applied they remain very slow as you can see here. We will come on to motion tests in a moment.
 

OD Normal

Switching up to the 'Normal' OD mode brought about some positive changes to response times. With overdrive now turned on, there was some variation in performance depending on the refresh rate. Above we can compare the pixel response times at 60Hz refresh rate and the native maximum 144Hz, and overclocked maximum 200Hz. At 60Hz the average G2G was a bit better at 13.9ms, but still this was slow in certain circumstances. Some transitions still proved to be problematic. There wasn't any overshoot introduced though so the overdrive impulse seemed to be quite modest, at least at 60Hz refresh rate.

At 144Hz G2G average had reduced down to 11.4ms now which was a bit better, but with some transitions still being very slow, like those from black to grey shades (e.g. 0-50 and 0-150) there was still some issues here. Some of the moderately slow transitions from the 60Hz measurements had been sped up though which was good news and if we ignore the few problematic transitions, the other response times were actually very good. The same thing can be said for the overclocked 200Hz mode although there was very little difference to the 144Hz setting overall in the response time measurements. We will look at some motion blur tests in a moment. There was overshoot measured in this small sample set at the higher refresh rates of 144Hz and above, getting progressively more noticeable as a result of the overdrive impulse being boosted. Our subsequent motion tests show further analysis as well in a moment.

OD Extreme

Finally we tested the 'Extreme' OD mode. There was an improvement in measured response times again but it was not by a huge amount. At 60Hz refresh rate they dropped from 13.9ms in normal mode down to 11.8ms, but this was still slow overall because of some of the problematic transitions. There was still an issue with a couple of very slow transitions from black to grey (0-50 and 0-150) even with this maximum overdrive setting being used. There was minimal overshoot introduced at 60Hz, again showing the overdrive impulse was fairly modestly applied even while set at the 'extreme' setting.

At 144Hz refresh rate, the response times dropped down to 9.6ms G2G average. Some transitions had been sped up now and only the 0-50 transition remained a real problem. In fact, if we ignore that one transition the average response times were more like 5.9ms G2G with some as low as 1.9ms which was very good. However, to achieve these response times the overdrive impulse had to be turned up very high and this lead to some high levels of overshoot, and obvious dark and pale trails in motion tests.

The same thing can be said for the 200Hz setting. Overall the average response time was now 8.9ms, but would be 5.0ms G2G if we ignored the problematic 0-50 transition. Again to achieve these low numbers the overdrive impulse was being applied too aggressively and so there were very high levels of overshoot. This was again very obvious in practice.

0-50-0 transition, OD Extreme
scale = 20ms per horizontal grid

Above is the oscilloscope graph for the problematic 0-50 transition. You can see the extremely slow rise time here, no matter what the OD setting or refresh rate selected. Very slow indeed. Apart from a few problematic transitions the other response times were mostly very good, but these inconsistencies did cause some problems in practice.
 

So those tests measure the pixel response times in each of the OD settings. With OD off, there was very little change in response times at different refresh rate settings, since there was no overdrive impulse being applied, and therefore no overdrive impulse to be dynamically altered by the G-sync module. With OD pushed up to normal or extreme, there were some  modest improvements in response times, which were impacted a little with the varying refresh rate. The slow response times in some transitions recorded for this screen presented some problems as you increase the refresh rate unfortunately. We will try to demonstrate that here, to give an idea of what you can see in practice running some simple motion tests. We used the familiar PixPerAn tool, testing the screen in each of the OD settings and at a selection of refresh rates from 60Hz all the way up to 200Hz (maximum overclock).

Let's concentrate first of all on the OD off setting, and how the performance varies with changing refresh rates - look at the first column in the above image. We know from our oscilloscope measurements that there's very little change in actual pixel response times at different refresh rate settings. As a reminder, we measured 16 - 17ms G2G average in that mode, with some transitions being extremely slow indeed. Even though we know response times are very similar at different refresh rates, you see something different with the naked eye here. As you increase the refresh rate the motion clarity gets progressively worse. By the time you reach the native 144Hz maximum, or even the overclocked 200Hz maximum there is a massive amount of blurring and the image is just a streaky, blurry mess. If response times aren't changing, what is the reason for this?

The reason is that the response times aren't fast enough to keep up with the frame rate of the higher refresh rate settings. For example, at 85Hz there is a new frame displayed every 11.76ms. At 100Hz a new frame every 10ms, at 144Hz every 6.94ms and at 200Hz every 5ms. To be able to cope with the frame rate the response times of the panel need to be reliably and consistently faster than those changes in frames. So for 85Hz operation you'd need reliable response times of <11.76ms. If the response times aren't faster than this then you are left with a lot of motion blur. You will see this from many overclocked Korean models, where you can boost refresh rate often up to 100 - 120Hz, but on panels which are fundamentally slow. Here, it's a problem, as with OD off we measured 16 - 17ms G2G average, with many transitions being much, much slower. That's barely fast enough for 60Hz operation (a new frame every 16.66ms). So if you use OD off and increase the refresh rate on this screen to anything above 60Hz, the motion clarity just gets worse and worse. So to summarise, if you use OD off, don't go above 60Hz! Whether you'd ever lead OD off is unlikely to be honest, so let's think more about the 'normal' and 'extreme' modes.
 

The OD normal mode is the middle column in the image above. In that setting we saw some minor improvement in motion clarity as you move from 60Hz to 85Hz and 100Hz. The moving image just looked a little sharper and clearer, but not by much. This is a result of the slightly boosted response times, along with motion clarity benefits of an increased refresh rate. Some slight dark trailing began to appear but it was not too distracting or severe. Levels of blurring varied depending on the content and colour transitions, with the response times measured at only 11.4ms G2G average (again with some very slow examples). Some scenes were nice and smooth with low levels of smearing where response times were low, but in certain circumstances a noticeable smearing was introduced where the response times just couldn't keep up. This was particularly evident on darker content. The motion clarity was certainly not as smooth and clear as fast IPS and TN Film gaming panels overall. However, it was good for a VA type panel on the most part.

As you move up to higher refresh rates like 144Hz and 200Hz the behaviour changed somewhat. Ignoring the few very slow transitions, the rest of the response times were just about fast enough to cope with 144Hz operation, although by that time you could detect additional noticeable dark overshoot in this OD normal mode since the overdrive impulse was now being applied more aggressively. As you increased to 200Hz the overshoot became more pronounced again, but the blurring was a little less. With OD at normal, you can just about get away with using the full range of refresh rates from a frame rate point of view, although in some colour transitions you may see enhanced blurring caused by the fact that some response times can't keep up with the frame rate demands. In an ideal world you would be able to achieve response times reliably of <6.94ms for 144Hz operation, and <5ms for 200Hz. Some transitions reached this level, but some did not. Some were very slow indeed as we've mentioned. With the added significant overshoot introduced at the higher refresh rates we question the practical use of 144Hz and above refresh rates with OD set to normal for some users.

We felt the screen was ok at up to around 100 - 120Hz without the overshoot becoming distracting and noticeable. At these levels there was little excess blurring or smearing introduced due to some slow pixel changes in most cases, although some scenes showed problems. The overshoot was kept at fairly low levels and not really a problem though up to 120Hz. Sadly we felt the panel was not capable of achieving low enough response times to reliably support anything higher, including the 144Hz native maximum refresh rate, and the overclocked range from 160 - 200Hz. The smearing becomes more obvious and the overdrive impulse starts to get applied too aggressively to try and keep up, and so the resulting overshoot is a big problem. You might want to experiment with different settings above 120Hz perhaps, although we felt the performance at 120Hz gave a better overall appearance.
 

Finally the OD extreme mode was tested, and really we can only advise you to leave this setting alone. The response times are mostly fast enough to allow operation at 144Hz without excess blurring and smearing being introduced, as long as you ignore the few problematic transitions like 0-50 (measured at 50ms at 144Hz). Even at 200Hz they are just about low enough. The problem with OD extreme is that there's too much overshoot at anything above 60Hz, and so you are left with dark trails and halos behind the moving objects. They become very severe at higher refresh rates and so this extreme mode should be avoided.
 

Overall this was a bit disappointing, but we will try not to be too harsh. The panel has a native 144Hz refresh rate from AU Optronics, and Acer have done a good job boosting this to 160, 180 and 200Hz which seemed to work pretty well. However, with the pixel response times being a bit slow in some cases, it can't quite keep up with the intentions. OD off just creates a mess at anything above 60Hz with blurring and smearing being very pronounced. Not really a problem as you're unlikely to use that mode. The OD extreme mode is predictably too aggressive with the overdrive impulse and so again anything above 60Hz isn't really usable. Not for blurring and smearing reasons, but for the obvious overshoot and dark trailing. This leaves us with OD normal mode which is better thankfully. However the response times in certain cases were very slow, and overall they were  not on par with the levels you can reliably achieve from TN Film and modern high refresh IPS panels. Some transitions were very slow and problematic and so in some colour transitions you can see excess smearing. In other cases the image was clearer. This is fairly typical of VA panels to be honest. We felt that once you get above 120Hz the overshoot becomes a bit too noticeable and so along with some enhanced smearing we felt the higher refresh rate range was a disappointment. We don't think it's Acer's fault either. You can tell from the OD extreme mode that the overdrive circuit they've applied isn't being too conservative. The VA panel just doesn't quite seem to be fast enough overall to keep up with the refresh rate it supports and this is down to AU Optronics. We haven't tested the BenQ XR3501 which is the other 35" screen using this same panel (144Hz max), but we gather that it seems to have disappeared from supply while BenQ perhaps look at similar issues. We will seek some further feedback from BenQ if we can on that. So to summarise, stick with OD normal but the response times aren't as fast as we'd like and in our opinion not really sufficient to support refresh rates above ~120Hz reliably.

Obviously for a screen that can support 200Hz refresh rate, that's a bit of a shame but if you think about it another way, it's not all bad. For a start, there are very few high refresh VA panels in existence, and so this is one of the few options for people who like the high contrast ratio, low glow and general performance of VA panels. A VA panel which can reliably run at 120Hz well is still very attractive and the response times are better than most VA panels around. Secondly consider the power of your system and whether you can realistically output 2560 x 1080 at >120Hz regularly? Does the performance above 120Hz matter too much to you? Finally, you will see from tests in the following sections that the ULMB feature is good at reducing perceived motion blur, and given that has a maximum refresh rate of 120Hz you might prefer to stick with 120Hz + ULMB anyway for gaming.

Refresh Rate

One of the most interesting features of the Z35 is the overclockable refresh rate. The panel itself is designed to run at 144Hz by AU Optronics and that's the maximum 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 up to 200Hz maximum here. As with the overclockable X34 model we tested before (60Hz native to 100Hz overclocked) this is an "up to" maximum on the Z35. The reason for the "up to" 100Hz message is because you can customise the maximum refresh rate you want to select in the OSD, in a few steps at 160, 180 and up to 200Hz. We have been told that overclocking does NOT affect the Acer warranty, which carries standard warranty terms and is available via the Acer support website. We are told that once enabled in the OSD the monitor will report back to your operating system the supported refresh rates and it should not matter what graphics card vendor you are using. Based on this you should be able to get 200Hz in most cases it seems.

Once you enable the overclocking feature you can choose then the max refresh rate which you want to be available in Windows, in addition to the default 144Hz maximum. You then just have to use the "apply and reboot" option which restarts the monitor.

     
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. 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 were detected properly and worked fine in Windows with no visible artefacts or flickering. Some users had reported some coil whine from the smaller X34 screen when using overclocked refresh rates on the but we heard nothing different at any refresh rate here on the Z35, or indeed when we tested the X34. 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 200Hz refresh rate. This overclocking seemed to work very well, at least from our test systems (both NVIDIA GTX 750 and AMD Radeon R9 290 series) and we were impressed.

One thing we did notice on our NVIDIA test system was an odd behaviour with the overdrive impulse at the maximum 200Hz refresh rate. If you observe the moving car in the PixPerAn tests you can see this issue. Approximately every 3 seconds the overdrive impulse seemed to "jump", causing a large amount of overshoot to momentarily appear in front of the moving object, before quickly reverting to its normal operation. It was a very quick change but you could see it clearly. At 200Hz and with OD set to normal there is some dark trailing behind the car normally. This disappears momentarily and a more severe dark and pale overshoot appears in front of the car instead. It was an odd behaviour and we can only assume it was an artefact resulting from the excessive refresh rate boost above the native 144Hz. At 160 and 180Hz overclocked refresh rate modes this did not appear, so it seemed to be only when pushing the screen to the limit of its refresh rate overclock. Perhaps this will vary on other systems and graphics cards although we found it did the exact same thing on our AMD Radeon system as well.

As we've already discussed though, we felt the overshoot became too noticeable when you start to get above 120Hz so we would question the practical use of these higher refresh rates. 120Hz is still a very decent refresh rate and should offer smooth motion and high frame rates. The refresh rates above this introduce too many issues we felt and so might not be much use to some users. If you're using G-sync as well, you would probably be best sticking with either 120Hz maximum or the native 144Hz as the maximum refresh rate, rather than using any overclocked settings, and allowing the G-sync module to dynamically control the refresh rate between 30 - 120/144Hz.

More Detailed Measurements
OD Normal, 120Hz 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 a refresh rate of 120Hz since that in our opinion it delivered the optimal response time performance without too much overshoot and dark smearing being introduced. You can of course push the refresh rate up to the native 144Hz or even one of the overclocked settings up to 200Hz. This brings the response times down a bit, but we felt the overshoot trade-off was not worth it.

The average G2G response time was more accurately measured at 9.0ms which was not bad overall for a VA panel. There are some transitions which are problematic, those changing from black to grey shades. You can see for instance that the 0-50 transition is extremely slow at 51.5ms, then they get a little faster as the grey shade becomes lighter. These slow response times drag the average down a lot though, and in fact if you ignore those 4 in red/orange, the response times would have been 5.7ms G2G average which would have been excellent. With some slow transitions plaguing the panel, some smearing and blurring is evident in practice. The 120Hz refresh rate used here provides a high frame rate and brings about some motion blue reduction benefits compared with lower refresh rates. It also does boost the response times somewhat compared with 60Hz and 85Hz for instance so there's an obvious benefit in running at 120Hz here. If you push the refresh rate up higher, there are some small improvements in response time measurements (although not massive), however at the cost of more noticeable overshoot artefacts.

At 120Hz there was very little overshoot, with only a couple of transitions showing anything, and even then at fairly low levels. Once again we felt that 120Hz provided the optimum balance between response times and overshoot. If you push the refresh rate higher, the overdrive impulse is dynamically affected and boosted to try and ensure the response times can keep up with the frame rate demands. In doing so, above 120Hz we saw a progressively more noticeable dark trailing and smearing introduced. By the time you reach overclocked refresh rates it is distracting and problematic. We think 120Hz would provide  the best balance for many users. Not to mention this is then a much lower demand on your system and graphics card than trying to output 2560 x 1080 @ 200Hz.

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 optimal 120Hz refresh rate the response times out-performed other recent VA panels like the BenQ BL3200PT and GW2760HS by a little way, and there were obviously significant improvements in refresh rate support compared with those 60Hz-only models. The VA based Eizo Foris FG2421 was a bit faster overall though but not by a huge amount. Motion clarity wise, you could say the Predator Z35 is quite like having a 35" ultra-wide version of that Eizo screen in many ways in practice. Response times and motion clarity couldn't keep up with the range of modern high refresh rate IPS-type panels like the Acer XB270HU (5.5ms) or Asus ROG Swift PG279Q (5.0ms) for instance. Nor could it keep up with fast TN Film screens like the BenQ XL2730Z (3.4ms).

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.

35" 4ms G2G AU Optronics AMVA @ 120Hz (OD = Normal)

In practice the Acer Predator Z35 performed best with OD at normal and at 120Hz refresh rate. There were moderate levels of blurring evident, and there was only low levels of overshoot evident. The support for higher refresh rates provided additional levels of motion clarity and image smoothness which surpassed what was possible from 60Hz VA panels certainly. The additional G-sync and ULMB support for NVIDIA users will also be of real benefit.

35" 4ms G2G AU Optronics AMVA @ 120Hz (OD = Normal)

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

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

The above images show a comparison with the 34" Acer Predator X34 (G-sync) and Acer XR341CK models (FreeSync version). The two 34" models showed less noticeable blurring we felt and better motion clarity. A result of improved response times (more so with the X34), freedom from the low levels of overshoot we saw on the Z35 and also without the issues of some particularly slow transitions which affected the VA panel of the Z35.
 

Ultra Low Motion Blur (ULMB)

The Predator Z35 also features an integrated Blur Reduction Backlight system, dubbed "Ultra Low Motion Blur" (ULMB). This is linked to the G-sync module and is provided on most G-sync enabled screens that have a native high refresh rate. 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 (updated 17 March 2015) 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 strobed backlight with simple user control from the menu and with better implementation than LightBoost methods.

The ULMB feature is accessible from the 'display' section of the OSD menu. 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 rates. 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 "Pulse Width" which allows you to control the duration of the backlight strobes. A shorter "on" period can help reduce perceived motion blur even more, but at the cost of screen brightness. 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. We actually found the flicker produced by this relatively low frequency strobe noticeable with the naked eye and a bit annoying. We suggest using at least 100Hz to avoid most of that.
 

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). The above is with pulse width at the default 100. We can also see what impact on the strobing it has if you lower the pulse width setting.

As you reduce the pulse width setting you are adjusting the 'on' period of the strobe. 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.
 

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 we'd seen on other ULMB-enabled monitors at 120Hz including the Asus ROG Swift PG278Q and PG279Q for instance and so is likely fixed for the NVIDIA ULMB feature at this refresh rate.

Pulse Width Setting - Brightness Range (120Hz)

We tested the brightness output of the screen when ULMB was turned on at 120Hz. 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 111 cd/m². This should be enough for some 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 for the majority of users. You can achieve a slightly brighter display if you use the feature at 85 or 100Hz since the strobes are less frequent, but it's not a significant amount.

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, 120Hz)

We also wanted to test the brightness range when leaving PW at its default 100, and changing the brightness control of the screen instead. This leaves the strobe behaviour alone, operating as it does with PW at 100, and instead just dims the backlight. The table above confirms the range available through that control. You can achieve a slightly brighter display if you use the feature at 85 or 100Hz since the strobes are less frequent, but it's not a significant amount.

When you enable the ULMB feature the actual brightness level showing in the OSD menu is still the same as whatever you had it set at before (let's say our calibrated 21% for arguments sake). So the menu shows 21% still but in fact when you first enable ULMB it operates with maximum brightness for that feature. If you then turn off ULMB it reverts back to the 21% brightness you had before. So that part is good and doesn't cause any problems. If for some reason you wanted to run the ULMB at a lower brightness setting you'd have to manually change it from the 21% showing in the menu to whatever level you wanted (let's say 90%). When you then turn off ULMB the brightness stays at that new 90%. We can't really see any need to run at anything less than 100% when using ULMB so actually it all works nicely. Just leave the brightness control alone in the OSD and it will switch from your normal calibrated setting to 100% brightness ULMB, and then back again nice and easily. If for any reason you wanted a darker ULMB operation we recommend just lowering the pulse width setting a bit which then doesn't affect the brightness control, and also will bring about some minor improvements in blur reduction too.

Maximum Blur Reduction Brightness - Display Comparison

For ease of reference we have also provided a comparison table below of all the blur reduction enabled displays we've tested, showing their maximum luminance before blur reduction is turned on (normal mode) and their maximum luminance with the feature enabled. This will give you an idea of the maximum brightness you can expect from each model when using their blur reduction feature, if that is important to you. A lot of people want a brighter display for gaming and sometimes the relatively low maximum luminance from blur reduction modes is a limitation.

These comparisons are with the refresh rate as high as is available for the blur reduction feature to function. For most this is at 120Hz, but some also support the feature at higher. You can achieve a slightly brighter display if you use the feature at 85 or 100Hz since the strobes are less frequent, but it's not a significant amount. That can also introduce more visible flicker in some situations.

Note: Pulse Width setting at max where applicable.
*Note 2: The Acer XB270HU was later updated to include a 120Hz mode, which will produce a slightly darker maximum luminance

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 we've tested.

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. Some of the dark smearing we had seen before was cut off by the strobing of the backlight and the motion clarity was certainly much better. We used the BlurBusters full-screen TestUFO online motion test 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 low levels of cross-talk here in the central region and the image looked pretty good. It wasn't as clear as some other screens we've tested since the response times are not as good, but it's a marked improvement over normal operation for sure. 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. As ever, you cannot use ULMB at the same time as G-sync so keep that in mind.

Additional Gaming Features

• Aspect Ratio Control - The Z35 has 3 options listed in the menu for aspect ratio control through the OSD 'setting' section menu. There are options for full, 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) 7.17 Pixel Response Time Element 2.85 Estimated Signal Processing Lag 4.32 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 7.17ms. Approximately 2.85ms of that can be accounted for by pixel response times (if we ignore the few very slow transitions and take half of the 5.7ms G2G average we are left with), leaving an estimated signal processing lag of only 4.32ms. 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:

• 35" 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.

• 2560 x 1080 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 359 cd/m² and a good minimum luminance of 54 cd/m². This should afford you very good control for different lighting conditions. 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 thanks to the VA-type panel at 2813:1 after calibration. Detail in darker scenes should not be lost as a result and this is certainly a strength of the VA panel technology used here.

• 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.

• Adequate pixel responsiveness which should handle fast moving scenes in movies without issue. No overshoot issues as long as you stick to 120Hz or less and the 'Normal' OD setting. You may see issues with smearing in certain scenes caused by some slow response times in places.

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

• Viewing angles are a little behind what we were hoping for and there is noticeable gamma and colour tone shift as you change your viewing position. The image becomes quickly washed out so we wouldn't advise using this screen for viewing from anything other than head on really. There is at least no pale IPS-glow on dark content like you see from the majority of IPS-type panels.

• 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 9W 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.
  
   

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.

The Z35 is certainly an interesting screen to consider, and with its massive 35" ultra-wide screen size it is a real beast of a monitor. Being as big as it is, and with a considerable curve it is very immersive for gaming and multimedia and these are certainly the screens primary target uses. We were impressed by the decent range of features and extras offered by this model. NVIDIA G-sync and ULMB are of course very welcome and offers great benefits for gaming. Added features like the ambient light system were also nice extra touches we felt. Performance wise it's quite interesting as VA panels are rarely used in gaming screens and this is one of the few available. The high refresh rate offers a big bump in frame rates and performance over the wide range of 60Hz-only VA panels available so far, so that's an obvious selling point here. Thanks to the G-sync module the lag was basically non-existent as well which was positive. VA technology certainly has it's advantages when it comes to contrast ratio, offering deep blacks and also the freedom from the pale glow you see from IPS panels in darker content.

In other aspects of gaming the screen struggled a bit though. The response times were ok overall but some transitions caused problems and were very slow. You end up with obvious dark smearing and blurring in certain circumstances which is a shame, and at the moment a limitation of VA technology it seems. The additional ULMB was very good at improving motion clarity and did help cut back some of that smearing if you want to use that feature. The very high refresh rates enabled by the overclocking feature couldn't really be fully realised though sadly, as we felt that response times were just not fast enough to handle the frame rate demands, and the overshoot introduced by the aggressive overdrive circuit was too obvious. It's still very capable as a VA option with a high refresh rate of 120Hz, with G-sync and ULMB support but the 200Hz overclocking feature couldn't quite keep up sadly.

In other non-gaming areas the low resolution and large font size aren't great for office work, unless maybe you're used to low DPI already. However, the backlight offered a good range of adjustment and the flicker free operation was definitely pleasing. Default setup was also decent and required little change to achieve a reliable performance. Viewing angles were not as good as we were expecting sadly. The feature set was reasonable, with a fair set of connectivity options and stand adjustments provided and in line with other modern G-sync screens.

Overall if you are after a VA screen for gaming this is certainly one of the best options available. VA technology isn't quite there it seems to keep up with some of the impressive specs and features available, but it's still very capable and provides plenty of performance power in many areas.