ASUS PA278QV

Interlace pattern artifacts

On some monitors, particularly but not exclusively those with high refresh rates, interlace patterns can be seen during certain transitions. We refer to these as ‘interlace pattern artifacts’ but some users refer to them as ‘inversion artifacts’ and others as ‘scan lines’. They may appear as an interference pattern, mesh or interlaced lines which break up a given shade into a darker and lighter version of what is intended. They often catch the eye due to their dynamic nature, on models where they manifest themselves in this way. Alternatively, static interlace patterns may be seen with some shades appearing as faint horizontal or vertical bands of a slightly lighter and slightly darker version of the intended shade. We did not observe either artifact type on this monitor.

Responsiveness

Input lag

A small utility called SMTT 2.0 was used alongside a sensitive camera to analyse the latency of the PA278QV, with over 30 repeat readings taken to help maximise accuracy. Using this method, we calculated 5.12ms (under ½ a frame at 75Hz) of input lag. At 60Hz we measured a marginally higher but still reasonable 6.73ms. The input lag measured here reflects both the element you ‘see’ (pixel responsiveness) and the element you ‘feel’ (signal delay). It indicates a fairly low signal delay which most users should be just fine with. Note that we don’t have the means to accurately measure input lag with Adaptive-Sync active in a variable refresh rate environment.

Perceived blur (pursuit photography)

Our article on responsiveness explores the key aspects of monitor responsiveness. Chief amongst these is the concept of ‘perceived blur’, which is contributed to by both the movement of your eyes as you track motion on the screen and the pixel responses of the monitor. The first element dominates on a modern monitor, but pixel responses also play a key role. The responsiveness article also covers a photography technique referred to as ‘pursuit photography’. This uses a moving rather than stationary camera to capture motion in a way that reflects both elements of perceived blur. This contrasts with the use of a stationary camera, capturing motion in a way that only reflects pixel responsiveness.

The images below are pursuit photographs taken using the UFO Motion Test for ghosting, with the test running at 960 pixels per second. This is a good practical speed for capturing such photographs and highlights both elements of perceived blur nicely. The UFOs move across the screen from left to right at a frame rate matching the refresh rate of the display. The monitor was tested at 60Hz (directly below) and 75Hz using various ‘Trace Free’ (TF) settings: ‘40’, ‘60’, ‘80’ and ‘100’. ‘0’ and ‘20’ were excluded from this analysis as the monitor just shows a gentle ramp up in pixel overdrive from ‘0’ to ‘40’. Even a TF setting of ‘40’ offers fairly gentle acceleration and there’s no real reason to use anything lower. All background shade levels (dark, medium and light) were used to highlight a range of pixel transitions between different shades. The final column shows reference displays, where possible, set to what we consider their optimal pixel overdrive setting for the refresh rate. The first reference screen is the ViewSonic XG270QC, a 27” VA offering. The second reference is the ViewSonic XG270QG, a responsive IPS model.

Note that wavy patterns surrounding some UFOs in the background are slight image retention. This was only observed during this test and is something we’ve seen on various monitors before. It soon disappeared when using monitor normally.



The UFOs appear quite broad and unfocused without clear internal detailing. This reflects a moderate degree of perceived blur due to eye movement. Some trailing can also be observed behind the UFOs in some cases due to weaknesses in pixel responsiveness. With TF set to ‘40’, there’s a little ‘powdery’ trailing behind the object for the dark background (top row) and a very fine dusting for the medium background (middle row). The light background (bottom row) shows a very clean performance. There’s nothing here that’s like the clearer (‘smeary’) trailing observed on the VA reference screen. Setting TF to ‘60’ cuts down on the powdery trailing and gives very little to complain about for these transitions, really. A small amount of overshoot (inverse ghosting) is visible as a faint ‘shadow’ behind the UFO for the medium background but nothing substantial. Things look similar to the fast IPS reference screen. Setting TF to ‘80’ introduces more obvious overshoot with bright and colourful trailing – this becomes very strong if ramping up TF to ‘100’. From this analysis we consider ‘60’ to be the optimal Trace Free setting and this is reflected by broader analysis. There is a bit of overshoot for some transitions not shown here (we explore this later), but it’s not extreme or widespread. If you dislike it setting TF to ‘40’ would be a good fallback. Below you can see how things appear with refresh rate increased to 75Hz.



The UFO now appears slightly narrower, reflecting a slight decrease in perceived blur due to eye movement. Not a substantial change as the refresh rate is only 1.25 times what it was before, but still an improvement. The trailing behaviour is fairly similar, with some ‘powdery’ trailing appearing slightly more pronounced. Really this just reflects the fact that the pixel response requirements for optimal performance have been raised by 25%. We again consider ‘60’ the optimal and best-balanced TF setting, without the more distinct ‘powdery’ trailing of ‘40’ and lack of stronger overshoot that creeps in at ‘80’ or beyond.

The monitor has a mode called Rapid Rendering that can be activated if Adaptive-Sync is disabled. This is a strobe backlight feature that causes the backlight to flicker at a frequency matching the refresh rate of the display – 75Hz only in this case. Sensitivity to this flickering of the backlight varies, but this is a relatively low refresh rate for a strobe backlight setting so it has strong potential to cause bother. We certainly found it unpleasant. Even if the flickering isn’t something that you find actively bothering, the flickering of the backlight can still accelerate eye fatigue. The pursuit photos below show the mode in action. Trace Free is not adjustable with this setting active, but there are two Rapid Rendering modes available: ‘Standard’ and ‘Advanced’. The ‘Advanced’ setting uses a shorter pulse width than ‘Standard’, meaning the backlight spends a relatively long period in its ‘off’ phase. The screen is therefore dimmer in comparison, but there’s a potential improvement to motion clarity with this shorter pulse width as well.



With RR active, the UFOs are significantly narrower with clearer internal detailing. There’s no real difference between the ‘Normal’ and ‘Advanced’ setting here when observed by eye, aside from the brightness. This brightness difference can cause some differences in how the images appear with both settings as the camera responds slightly differently in both cases. You can count the small notches and the segmentation of the UFO is more distinct. You can see some clear trailing behind the object, appearing fragmented with multiple repetitions due to the strobing of the backlight. For the dark background and lesser extent medium background you can also a fringe behind the UFO cockpit that’s an eye-catching and vivid red shade. It’s also visible a bit in front of the UFO for the dark background. This is due to the phosphors of the backlight and is something we observed when gaming (along with associated issues), as explored shortly. There is some overshoot visible for the medium background in particular as a ghostly final trail, whilst the earlier trail is a reasonably bold repetition of the object. The repetitions can be broadly termed ‘Strobe Crosstalk’ and can appear in different places and with different intensity depending on which section of the screen you’re observing. That’s because not all parts of the screen refresh simultaneously – you can see this behaviour in the image below.



Further up the screen you can see fairly strong overshoot behind the UFO as well as a slight magenta fringe in front. Towards the centre of the screen the fringe shifts behind and a fairly distinct repetition of the object is visible. Plus a ‘shadowy’ overshoot trail behind that. The repetition becomes very bold further down the screen, eventually melding into the object so it’s about as bold and clear as the main UFO. The final overshoot trail is also distinct and inky further down the screen. We explore the implications of this clear strobe crosstalk and other factors to consider a bit later on.

Note that we will not be including a section on overclocking, as the monitor refused to display an image if set much above 75Hz.

Responsiveness in games and movies

On Battlefield V there was a moderate degree of perceived blur. This was primarily caused by eye movement and linked to the 75Hz refresh rate of the display. The bump up from 60Hz to 75Hz slightly reduced this perceived blur due to eye movement and slightly enhanced the ‘connected feel’. That’s the precision and fluidity that’s felt when interacting with the game world – this difference was marginal compared to a more significant boost. But it was still a nice little edge to have. There were no major weaknesses from pixel response times and the monitor put in a strong 75Hz performance. There was a little ‘powdery’ trailing in places, usually where darker shades were involved. But this was relatively faint and short-lived and not at all widespread. We also observed some overshoot, particularly if darker objects were set against a lighter background. Such as a medium-dark brown tree trunk against a bright daylight sky, which produced a bit of ‘halo’ trailing that was somewhat brighter than the background shade. This was not particularly bright, strong or eye-catching overshoot nor was it widespread.

We made similar observations on Shadow of the Tomb Raider. The 75Hz refresh rate again provided a slight advantage over 60Hz with respect to the perceived blur due to eye movement and ‘connected feel’. Nothing substantial but still noticeable to us. There were plenty of dark shades on this title, but a good variety of shade levels really which showcased a broad range of pixel transitions. Nothing really stood out as an obvious weakness and we found the 75Hz performance convincing. There was a touch of ‘powdery’ trailing in places and a bit of overshoot elsewhere, but this was quite minor really. We also observed video content of a range of frame rates, including ~24-30fps movie content (Netflix etc.) and 60fps YouTube content. The higher frame rate content was very similar to what we observed when gaming, so a pleasing performance overall. The lower frame rate content was also handled well. This has its fluidity limited by the frame rate itself and with this the pixel response requirements for a solid performance are low. No weaknesses were observed that could be tied to the monitor’s pixel response behaviour. Perhaps some very faint overshoot in places, but this remained well-blended and didn’t catch the eye.

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FreeSync – the technology and activating it

AMD FreeSync is a variable refresh rate technology, an AMD-specific alternative to Nvidia G-SYNC. Where possible, the monitor dynamically adjusts its refresh rate so that it matches the frame rate being outputted by the GPU. Both our responsiveness article and the G-SYNC article linked to explore the importance of these two elements being synchronised. At a basic level, a mismatch between the frame rate and refresh rate can cause stuttering (VSync on) or tearing and juddering (VSync off). FreeSync also boasts reduced latency compared to running with VSync enabled, in the variable frame rate environment in which it operates.

FreeSync requires a compatible AMD GPU such as the Radeon RX 580 used in our test system. There is a list of GPUs which support the technology here, with the expectation that future AMD GPUs will support the feature too. The monitor itself must support ‘VESA Adaptive-Sync’ for at least one of its display connectors, as this is the protocol that FreeSync uses. The ASUS PA278QV supports FreeSync via DP 1.2a and HDMI 1.4 on compatible GPUs and systems. You need to make sure ‘Adaptive-Sync’ is set to ‘ON’ in the ‘System Setup’ section of the OSD. On the GPU driver side recent AMD drivers make activation of the technology very simple and something that usually occurs automatically. You should ensure the GPU driver is setup correctly to use FreeSync, so open ‘AMD Radeon Software’, click ‘Settings’ (cog icon towards top right) and click on ‘Display’. You should then ensure that the first slider, ‘Radeon FreeSync’ is set to ‘Enabled’ as shown below. The top image shows the monitor connected by DP and the bottom image by HDMI.

The ASUS supports a variable refresh rate range of 48 – 75Hz. That means that if the game is running between 48fps and 75fps, the monitor will adjust its refresh rate to match. When the frame rate rises above 75fps, the monitor will stay at 75Hz and the GPU will respect your selection of ‘VSync on’ or ‘VSync off’ in the graphics driver. With ‘VSync on’ the frame rate will not be allowed to rise above 75fps, at which point VSync activates and imposes the usual associated latency penalty. With ‘VSync off’ the frame rate is free to climb as high as the GPU will output (potentially >75fps). LFC (Low Frame Rate Compensation) is not supported by this monitor, as that requires the upper limit (ceiling) to be at least 2x the lower limit (floor) of FreeSync operation. FreeSync is therefore deactivated if the frame rate falls below 48fps, with the monitor then respecting your choice of VSync and presenting you with either stuttering (VSync on) or tearing (VSync off).

To configure VSync, open ‘AMD Radeon Software’. Click ‘Settings’ (cog icon towards top right) and click ‘Graphics’. The setting is listed as ‘Wait for Vertical Refresh’. This configures it globally, but if you wish to configure it for individual games click ‘Game Graphics’ towards the top right. The default is ‘Off, unless application specifies’ which means that VSync will only be active if you enable it within the game itself, if there is such an option. Such an option does usually exist – it may be called ‘sync every frame’ or something along those lines rather than simply ‘VSync’. Most users will probably wish to enable VSync when using FreeSync to ensure that they don’t get any tearing. You’d therefore select either the third or fourth option in the list, shown in the image below. Above this dropdown list there’s a toggle for ‘Radeon Enhanced Sync’. This is an alternative to VSync which allows the frame rate to rise above the refresh rate (no VSync latency penalty) whilst potentially keeping the experience free from tearing or juddering. This requires that the frame rate comfortably exceeds the refresh rate, not just peaks slightly above it. We won’t be going into this in detail as it’s a GPU feature rather than a monitor feature.



Some users prefer to leave VSync enabled but use a frame rate limiter set a few frames below the maximum supported (e.g. 72fps) instead, avoiding any VSync latency penalty at frame rates near the ceiling of operation or tearing from frame rates rising above the refresh rate. The refresh rate displayed towards the top right of the OSD will reflect the frame rate of the content at the time you enter the OSD, if FreeSync is active and you’re within the VRR (Variable Refresh Rate) window. Finally, it’s worth noting that FreeSync only removes stuttering or juddering related to mismatches between frame rate and refresh rate. It can’t compensate for other interruptions to smooth game play, for example network latency or insufficient system memory. Some game engines will also show stuttering (or ‘hitching’) for various other reasons which won’t be eliminated by the technology.

FreeSync – the experience

As usual we tested various game titles using AMD FreeSync and found the experience similar in all cases. Any issues affecting one title but not another suggests a game or GPU driver issues rather than a monitor issue. For simplicity we’ll simply focus on Battlefield V as an example for this section. The graphics options allowed us to test the full VRR range of the monitor. With settings turned up a bit we commonly observed slight dips below 75fps. Without a VRR technology like FreeSync, such dips would cause obvious stuttering (VSync on) or tearing and associated juddering (VSync off). Obvious to us and others sensitive to such things, at least. These issues tend to be more noticeable at reasonably low refresh rates such as this, so it’s certainly nice having these interruptions removed.

As frame rate dropped further, because action intensified or due to graphics settings used, we noticed a drop off in ‘connected feel’ and increase in perceived blur linked to the drop in frame rate. This isn’t something FreeSync can help with – but the lack of tearing and stuttering from frame and refresh rate mismatches was nice. As refresh rate reduced the overshoot which was quite modest at 75Hz become more pronounced. It wasn’t ever extreme nor was it particularly widespread, so we didn’t really find it distracting or bothersome. Sensitivity varies and if you find it bothersome switching ‘Trace Free’ to ‘40’ should prove beneficial, which worked quite well still. Particularly towards the lower end of the VRR range. When frame rate dropped below 48fps the technology deactivated and tearing or stuttering resumed, depending on VSync status. LFC (Low Frame Rate Compensation) is not used as that would require the ceiling of operation is at least twice the floor of operation.

Nvidia Adaptive-Sync (‘G-SYNC Compatible’)

As noted earlier, AMD FreeSync makes use of Adaptive-Sync technology on a compatible monitor. As of driver version 417.71, users with Nvidia GPUs (GTX 10 series and newer) and Windows 10 can also make use of this Variable Refresh Rate (VRR) technology. When a monitor is used in this way, it is something which Nvidia refers to as ‘G-SYNC Compatible’. Some models are specifically validated as G-SYNC compatible, which means they have been specifically tested by Nvidia and pass specific quality checks. With the PA278QV, you need to connect the monitor up via DisplayPort and enable ‘Adaptive Sync’ in the ‘System Setup’ section of the OSD. This enables Adaptive-Sync on the monitor and will unlock the appropriate settings in Nvidia Control Panel. When you open up Nvidia Control Panel, you should then see ‘Set up G-SYNC’ listed in the ‘Display’ section. Ensure the ‘Enable G-SYNC, G-SYNC Compatible’ checkbox and ‘Enable settings for the selected display model’ is checked as shown below. Press OK, then turn the monitor off then on again so that it re-establishes connection – the technology should now be active. The image below is for a different model, but the model number is the only information on the page that differs.



You will also see in the image above that it states: “Selected Display is not validated as G-SYNC Compatible.” This means Nvidia hasn’t specifically tested and validated the display, not that it doesn’t work. Indeed the technology did work. It delivered an experience that was very similar to FreeSync, getting rid of tearing and stuttering in much the same way as frame rate fluctuated within its window of operation. A slight difference was that the floor of operation, at least with our GTX 1080 Ti, was 52Hz (52fps) rather than 48Hz (48fps). Not a difference worth stressing about in our view, but worth noting nonetheless. Our suggestions regarding use of VSync also apply, but obviously you’re using Nvidia Control Panel rather than Radeon Settings to control this. The setting is found in ‘Manage 3D settings’ under ‘Vertical sync’, where the final option (‘Fast’) is equivalent to AMD’s ‘Enhanced Sync’ setting. You’ll also notice ‘G-SYNC Compatible’ listed under ‘Monitor Technology’ in this section, as shown below. Make sure this is selected (it should be if you’ve set everything up correctly in ‘Set up G-SYNC’).



Finally, remember that the refresh rate displayed towards the top right of the OSD will reflect the frame rate of the content at the time you enter the OSD, if Adaptive-Sync is in use and you’re within the VRR window.

Rapid Rendering

We’ve already introduced the Rapid Rendering feature, its principles of operation and how it performs using specific tests. When using Rapid Rendering or any strobe backlight feature, it’s vital that your frame rate matches the refresh rate of the display exactly. Otherwise you’re left with very clear stuttering or juddering. This is because there’s very little perceived blur due to eye movement to mask it. As with most strobe backlight technologies, you can’t use Adaptive-Sync at the same time as Aim Stabilizer. You must be running the monitor at 75Hz and have ‘Adaptive Sync’ disabled in the ‘System Setup’ section of the OSD to activate the feature. We observed a few game titles using this feature but will just focus on Battlefield V running at a constant 75fps at 75Hz. We had the feature set to ‘Normal Mode’ as although this was dim, the ‘Advanced Mode’ was even dimmer. Brightness aside, our observations were largely similar even using ‘Advanced Mode’. This feature did significant cut down on perceived blur due to eye movement so in some respects motion on the screen was clearer. Objects didn’t break up into a blur even during rapid motion as they do during the normal sample and hold operation of the monitor.

We found the feature uncomfortable to use and there were plenty of visual disturbances when using it. The fact the screen was flickering at 75Hz was bothersome in itself. We also frequently observed flashes of colour such as cyan and magenta as we scanned our eyes across the screen or even moved them a short distance. The strobe crosstalk we observed using the UFO Motion Test for ghosting earlier was there in full effect. There were clear repetitions throughout the screen either in front of or behind objects. These were extremely strong and off-putting lower down the screen, but quite distinct centrally as well. It included very eye-catching colourful elements with a clear magenta or at times cyan tint. Put all of this together and this wasn’t a setting we liked to use for more than about 10 minutes. Some people may enjoy the benefits of this in terms of making it easier to track and engage enemies. Or they may have a specific work-purpose that benefits from the reduced perceived blur due to eye movement. It’s an interesting addition and not one you often see on 75Hz models, but it’s far from a ‘clean’ or comfortable experience.

Interpolation and upscaling

You may want to run the monitor at a lower resolution than the native 2560 x 1440, perhaps for better performance or to use a device such as a games console which doesn’t support native WQHD output. The monitor supports scaling functionality via any of its display inputs. As noted in the features and aesthetics section, a range of refresh rates (up to 60Hz) are supported at the Full HD resolution, whilst a ‘4K’ UHD upscaling mode is also offered. To ensure the monitor rather than GPU is handling the scaling process, you need to make sure the GPU driver is set up correctly. For AMD GPU users the monitor will handle the scaling by default, when gaming at non-native resolutions. Nvidia users should open the Nvidia Control Panel and navigate to ‘Display – Adjust desktop size and position’. They should ensure that ‘No Scaling’ is selected and ‘Perform scaling on:’ is set to ‘Display’ as shown below.

Considering the 1920 x 1080 (‘1080p’ Full HD) resolution, the monitor’s interpolation process provided a moderate amount of softening. This could be counteracted by adjusting ‘Sharpness’ in the ‘Image’ section of the OSD. We liked the balance struck at a setting of ‘30’, although everyone will have their own preferences. The image didn’t appear as it would natively on a Full HD screen of this size, but it didn’t have the obvious soft appearance that it did with the default sharpness level of ‘0’. Some elements appeared slightly filtered or oversharpened, but overall it made the monitor quite useable at the Full HD resolution and certainly better than some monitor interpolation processes we’ve come across.

As usual, if you’re running the monitor at 2560 x 1440 and viewing 1920 x 1080 content (for example a video over the internet or a Blu-ray, using movie software) then it is the GPU and software that handles the upscaling. That’s got nothing to do with the monitor itself – there is a little bit of softening to the image compared to viewing such content on a native Full HD monitor, but it’s not extreme and shouldn’t bother most users.

Video review

The video below shows the monitor in action. The camera, processing done and your own screen all affect the output – so it doesn’t accurately represent what you’d see when viewing the monitor in person. It still provides useful visual demonstrations and explanations which help reinforce some of the key points raised in the written piece.

Timestamps:
Features & Aesthetics
Contrast
Colour reproduction
Responsiveness (General)
Responsiveness (Adaptive-Sync)

Conclusion

The ASUS PA278QV is designed with colour accuracy in mind, as a member of the ProArt series. The monitor was well-built with good ergonomic flexibility, with a sensible home-office aesthetic. The resolution and screen size combination is one we’re very familiar with and is indeed a very popular one – and for good reason, it works well for a multitude of purposes. The monitor was nicely calibrated with respect to gamma and offered excellent flexibility in the OSD to adjust the gamma and colour channels. Following some slight adjustment to the colour channels and the usual brightness reduction the image was rich, natural and well-balanced. The colour gamut extended just a little beyond sRGB, providing faithful reproduction of sRGB content without obvious oversaturation or indeed undersaturation.

The contrast perform was much in-line with our expectations and indeed the panel specifications. Close to 1000:1 static contrast with a moderate but typical level of ‘IPS glow’ that ate away at some atmosphere in dark scenes. The screen surface was quite agreeable, with a light matte finish that preserved vibrancy and clarity relatively well. Plus a relatively smooth finish that kept brighter content free from any real graininess. Gamma consistency was strong, so detail level in dark scenes were appropriately maintained throughout the screen. The monitor also put in a solid 75Hz performance, providing a slight but not revolutionary edge compared to 60Hz models. The pixel responses were well-tuned with only a bit of overshoot and small amount of ‘powdery’ trailing for a slim number of transitions. The monitor also provided Adaptive-Sync which worked as it should on both our AMD (FreeSync) and Nvidia GPUs (‘G-SYNC Compatible Mode’).

Overall, we feel the monitor fits its brief very well. Colour reproduction within the sRGB colour space was its main strength, whilst it offers respective responsiveness and decent contrast on top. The monitor was also well built with excellent ergonomics and good OSD flexibility. Whilst it doesn’t offer support for extended colour spaces, high (triple-digit) refresh rates or HDR it’s certainly a competitively priced, well thought-out and capable all-rounder.

The bottom line; a solid all-round performer with a nod towards strong sRGB colour performance, respectable responsiveness and excellent ergonomics.

As an Amazon Associate I earn from qualifying purchases made using the below link. Where possible, you’ll be redirected to your nearest store. Further information on supporting our work.