AOC G2460PF

Responsiveness

Input lag

We used a SMTT 2.0, a small testing tool, alongside a sensitive camera, to compare the latency of the G2460PF with a range of monitors with known latency. Over 30 repeat readings were taken to maximise accuracy. Using this method, we measured 3.66ms (just over ½ a frame at 144Hz) of input lag. This value includes both the element of input lag you see (pixel responsiveness) and that you feel (signal delay) and indicates a very low signal delay that shouldn’t bother even sensitive users.

Perceived blur (pursuit photography)

In this article we take a detailed look at some key concepts related to monitor responsiveness. One of the most important take-home messages in that article is that what you see on a monitor is not just dictated by what the monitor itself is doing (i.e. the pixel responses) but also the movement of your eye as it tracks motion on the screen. This motion is actually a key contributor to perceived motion blur, generally more influential than the pixel responses on a modern monitor in fact. There is a specialist method of photography called ‘pursuit photography’ introduced in the article. This can capture not only what the monitors pixels are doing but also reflects the blur induced by eye movement.

The following images are pursuit photographs taken using the UFO Motion Test for ghosting, with the test running at 960 pixels per second. This proved a practical speed for these photographs to be taken and showed all of the key elements that constitute perceived blur on a monitor. Note that the interlacing lines on some shots are moire from camera and not visible when viewing the monitor. The ‘medium cyan’ background was used for all but the second row of photos, where a ‘light cyan’ background was used. A range of refresh rates (60Hz, 120Hz and 144Hz) and ‘Overdrive’ settings were used (Off, Weak, Light, Medium and strong). The final column shows reference monitor that is able to perform its pixel transitions fast enough so that they do not become a limiting factor. This is a Samsung S27A750D set to full brightness (this eliminates PWM) and using its optimal response time setting for the respective resolution (60Hz and 120Hz). Note that the ‘light cyan’ background was only used at 60Hz but not higher refresh rates because it showed some interesting differences there. At higher refresh rates performance for both the ‘medium’ and ‘light’ cyan backgrounds was quite comparable.

At 60Hz you can see a distinct trail behind the object that is not visible on the reference screen using ‘Overdrive = Off’. This is trailing from slower than optimal pixel responses. With the ‘Weak’ setting this trailing became fainter. It isn’t obvious in this image, but this is actually formed by a bit of overshoot (inverse ghosting) from strong grey to grey acceleration rather than conventional trailing caused by slower than optimal pixel responses. This trail is quite similar using the ‘Light’ setting and the ‘Medium’ setting, perhaps becoming a bit stronger progressively. The difference looks more pronounced in the shots given the presence of moire for the ‘Light’ and ‘Medium’ captures but not the ‘Weak’ capture – so apologies for that. Using the ‘Strong’ setting the overshoot becomes much stronger, with an obvious ‘halo’ effect from inverse ghosting behind the UFO.

At 60Hz with the ‘light cyan’ background, things are quite comparable with ‘Overdrive = Off’ to the ‘medium cyan’ background. Using the ‘Weak’ there is a fair degree of overshoot visible. This remains very similar using the ‘Light’ setting, although perhaps appears a little less obvious in the image due to colour tone. With the ‘Medium’ setting it becomes somewhat stronger and with the ‘Strong’ setting stronger still. The interesting difference between the ‘medium’ and ‘light’ cyan backgrounds here is really that the overshoot is a bit more pronounced, or indeed that it’s more obviously overshoot rather than conventional trailing.

At 120Hz you can see that the object itself is sharper (less blurred), reflecting the lower levels of perceived blur you would see now the refresh rate is higher. With the ‘Off’ setting there is a bit of trailing due to slower than optimal pixel responses. Setting the overdrive to ‘Weak’, ‘Light’ or ‘Medium’ yields similar results at this refresh rate. You can see a relatively faint trail behind the object, which again is mild overshoot rather than conventional trailing. It’s fainter than it is at 60Hz, especially when considering the red body of the UFO. With the ‘Strong’ setting there is extremely obvious overshoot, with the trail appearing either a bright blue (behind the body) or dark blue (behind the cockpit area) as different transitions are being performed. There are actually multiple overshoot trails here if you look carefully. Results at 144Hz were very similar to at 120Hz. Things are perhaps just a touch sharper as there is marginally less perceived blur, but really it’s a minor factor due to the relatively close refresh rates. The benefit here is certainly less significant than when comparing 120Hz or 144Hz to 60Hz.

This analysis reveals some interesting points to note about the pixel response behaviour of the monitor. At 60Hz the overshoot is generally more noticeable, particularly where the background is relatively light in shade. The ‘Weak’, ‘Light’ and ‘Medium’ settings seem very much comparable to one another at 120Hz and 144Hz, but the overshoot is perhaps a touch stronger on the ‘light cyan’ background using the ‘Medium’ setting. When considering a broader range of transitions and using the monitor in the real world (i.e. when gaming) it becomes quite obvious that the ‘Light’ setting is preferable to ‘Medium’ due to the reduced overshoot at lower refresh rates. It does not seem to suffer from being ‘slower’ in any appreciable way, either. The ‘Weak’ setting meanwhile seems very similar to ‘Light’ aside from adding a little bit of conventional trailing here and there. It is not exactly the clearest cut choice, but we opted for ‘Light’ due to it seeming to be the best optimised overall.

Responsiveness in games and movies

Where the frame rate of the game was in keeping with the 144Hz refresh rate of the monitor, the experience was very smooth and fluid on BF4. The connectedness to the game world was very strong, with the monitor seeming to respond very swiftly to user input. The level of motion blur at high frame rates was significantly reduced compared to on a 60Hz monitor as well, with the refresh rate and frame rate combination making tracking and engaging enemies to be that much easier. The game world and things moving about within it simply remained much sharper in comparison. The overshoot (inverse ghosting) observed in the previous section was there and fairly ubiquitous, but also quite faint on the whole. Some of the more obvious examples of this included dark objects with much brighter shades in the background, for example a dark metal gun turret on a vehicle with white clouds in the background. This contrast allowed the overshoot trail to be relatively visible, although it was still not particularly strong. Because the overshoot at 144Hz is generally fairly innocuous it should not be a problem for most users whilst they’re actually playing the game. The overall fluidity and lack of motion blur was far more noticeable, which this slight overshoot didn’t really detract from. Certainly compared to BenQ’s XL Series monitors running ‘AMA High’, for example, this was more subtle.

Dirt Rally also highlighted similar strengths and weaknesses in the response performance. The genre of game, at least at the level we play at, didn’t really benefit so much from the more connected feel provided by the high refresh rate and frame rate. The level of motion blur was greatly reduced at high frame rates (ideally matching the refresh rate), however. This meant that there was less blur during cornering in particular and the track was easier to focus on – something more capable players of this genre might appreciate. There was again widespread but quite faint overshoot, something that was not obvious enough to detract from the gameplay and was only really noticeable when you look out for it. Individual sensitivity to such things varies, but it’s a safe bet that most users will find this quite inconsequential at 144Hz and will still be able to appreciate the fluidity offered by the monitor.

FreeSync – the technology and activating it

AMD FreeSync is a variable refresh rate technology which we touch upon in the ‘Variable refresh rate’ section of this article. As with Nvidia G-SYNC, the idea here is to adjust the refresh rate of the monitor ‘on the fly’ to try to match the frame rate of the content. Both the responsiveness article and ‘G-SYNC’ article explain the importance of matching the frame rate and refresh rate, so we won’t go into detail about that. Essentially it’s important to eliminate tearing and juddering (VSync off) or stuttering (VSync on) that occurs due to misalignment between the frame rate of the content and refresh rate of the monitor. Compared to enabling VSync there is a reduction in latency in these fluid variable refresh rate environments as well, but unfortunately we don’t have an accurate way to measure this difference.

The technologies have a similar goal in mind, but go about achieving it differently. Whereas G-SYNC uses a proprietary ‘G-SYNC board’, that replaces the scaler and assistive electronics of the monitor, FreeSync makes use of ‘VESA Adaptive-Sync’. Adaptive-Sync is a capability integrated into some DP port controllers as an optional extension of DP 1.2a (sometimes dubbed ‘DP 1.2a+’). This enables variable refresh rate technology such as AMD FreeSync to be used. The key advantage to this over G-SYNC is that it reduces the cost to the monitor manufacturer and hence the end user. It also allows the manufacturer to have their usual OSD settings and port selection without Nvidia dictating this. The advantage of G-SYNC is that Nvidia have tighter control of the image setup and pixel overdrive implementation and ensure consistency throughout the refresh rate range. Furthermore, G-SYNC also has an interesting addition that FreeSync currently lacks (added feature of the new ‘Radeon Software Crimson’ suite called ‘Low Frame Rate Compensation’) that can help to minimise stuttering below the floor of operation. It is able to set the refresh rate to a multiple of the frame rate if the actual frame rate drops below the floor of G-SYNC operating. So if the frame rate was 20fps, for example, the monitor would set itself to 40Hz so that the frame rate divides into it evenly. Regardless of this, low frame rates are still low frame rates as we explore below.

The AOC G2460PF uses DP 1.2a with support for Adaptive-Sync and therefore supports AMD FreeSync. This requires a compatible GPU – there are some compatible models listed here, but it’s expected future GPUs from the company will also support this automatically. We are using a Club3D Radeon R9 290 royalAce for the purposes of this review. When you connect a compatible GPU to the monitor for the first time you are actually notified that you’re using a FreeSync-capable display and should enable the technology. To do this simply open CCC and navigate to ‘My Digital Flat-Panels – Properties (Digital Flat-Panel)’, ensure the checkbox at the bottom of the page is ticked and then press ‘Apply’. This page and checkbox is shown in the image below.

Note that the FreeSync operating range for the monitor is 35 – 144Hz. You must ensure you’re using the new driver, available to download from AOC’s website, otherwise you’ll be stuck with a 48Hz lower limit. Some users have reported issues with the FreeSync range even after installing that driver, so alternatively you can use this beta driver that was provided to us during the review. The GPU will respect your choice of ‘VSync off’ or ‘VSync on’ in the graphics driver, too. If you’ve got ‘VSync off’ you’ll get tearing or juddering below 35fps and above 144fps. If you’ve got ‘VSync on’ then you’ll get stuttering if the frame rate dips below 35fps and the usual VSync latency if the frame rate tries to rise above 144fps.

Because this is not a WHQL-signed driver, you’ll need to disable driver signature enforcement to install it. Advice on how to do this on Windows 8.1 and Windows 10 can be found here. Once you’ve got this disabled as advised, navigate to ‘Control Panel – System and Security – System – Device Manager’. Find the monitor, which should be listed as ‘Generic PnP Monitor’ (or alternatively with the correct name if you’ve already installed the official driver) and double click this. Go to the ‘Driver’ tab, press ‘Update Driver…’ and locate the .inf file from the beta. Restart the computer and you should be good to go.

FreeSync – the experience

On BF4 the game frequently dropped below 144fps (and indeed fairly often below 120fps as well) on our system. This was using fairly modest settings, not whacking everything up to ‘Ultra’. Without FreeSync enabled there was obvious stuttering (VSync on) or tearing and juddering (VSync off) as soon as the frame rate departed even slightly from the frame rate. Contrary to what some believe, enabling triple buffering does not remove this stuttering with VSync on – it can certainly help, but to us there is an obvious difference when the frame rate is laser locked to the refresh rate or when it departs from this even slightly. With FreeSync enabled these drops did not cause such effects and you were left with a much smoother and more playable experience. There can still be the occasional stuttering from other unrelated factors (memory issues, network latency etc.) but it made these slight drops in frame rate far more palatable.

As frame rate dropped further, which happened rarely on this title with the settings we were using, you don’t get any additional stuttering or tearing or anything like that with FreeSync enabled. But you do start to lose the benefits of the higher frame rates. One of the best ways of consistently hitting the frame rate hard in this title is to pump up the ‘resolution scale’ slider value so that the GPU has to work (potentially a lot) harder. Perceived blur increases and you can also start to observe more obvious overshoot issues as explored previously. Remember that at high frame rates (refresh rates) there is fairly widespread overshoot, but it appears as a faint trail that is generally a bit darker than the blend of the shade of the object. At lower frame rates (refresh rates) it appeared as a bright (halo) trail that is a fair bit brighter than either shade involved in the transition. If you move your character or viewpoint so that dark leaves of a tree are moving against a bright medium blue sky, for example, you would see this bright inverse ghosting trail as a sort of outline behind the leaves. This becomes increasingly bright and obvious as frame rate falls further, standing out reasonably well at 60fps and becoming rather obvious by 40fps.

On The Elder Scrolls Online (ESO), the frame rate generally fluctuated between 50fps and 100fps using the settings we like to use, but usually sat above 70fps. The game has a built-in 100fps cap, without any game file tweaks being applied, so this explains the upper limit. Without FreeSync the game would feel very smooth and fluid in less graphically intensive areas, such as indoors, where it could quite consistently run at 100fps. As soon as the pace of the action increased and the framerate fell at all below this there would be obvious tearing or stuttering. With FreeSync, the drops below this are much less noticeable – especially if the frame rate remains reasonably high (80fps+ for example). At times where the action really intensified the frame rate dropped further, sometimes coming quite close to the FreeSync floor of 35fps but very rarely dropping below this (and only momentarily if so). Again, FreeSync does not make low frame rates feel like high frame rates and there is still the associated increase in blur and a less connected feel in comparison. But the fluctuations are much less jarring than with the technology disabled. The aforementioned increase in overshoot also came into play at such frame rates, but we still feel this was preferable to setting the monitor to 100Hz+ without FreeSync.

We could go on to talk about various other titles and our experience with FreeSync, but really we’d just be repeating ourselves. It is undoubtedly a nice addition to the monitor. It allows you to have a nice level of smoothness and fluidity without interruption from tearing and stuttering, without having to sacrifice image quality such that your frame rate consistently matches the refresh rate. It’s certainly best if you can keep the frame rate as high as possible (low frame rates are still low frame rates), but these drops are still much less jarring than without the technology enabled. We also observed increasingly obvious overshoot as frame rate fell. This won’t bother all users but it would be nicer if it wasn’t there, particularly as there are no such issues if you leave the monitor at a high refresh rate such as 144Hz without FreeSync. This isn’t an issue with FreeSync itself, but rather how the pixel overdrive works on the monitor at lower refresh rates such as 60Hz and below.

Conclusion

Having tested quite a number of 24” 144Hz monitors, we know that providing a nice image ‘out of the box’ is not to be expected. We also know that, more often than not, you can improve the image with the right OSD tweaks – but will often need to go beyond that to get the best from the monitor. The AOC G2460PF did not buck this general trend, providing (centrally recorded) gamma that was simply too low regardless of the settings used in the OSD. We were able to improve the overall image representation significantly by fully calibrating with an ICC profile; something that isn’t really ideal for a gaming monitor. The image looked richer on the whole and far more pleasing. However; the usual TN issues remained regardless, most notably inconsistent colour reproduction with weakening saturation further down the monitor even from a normal seated viewing position.

So having established colour reproduction was not really the strong point of this monitor, particularly without intervention by an ICC profile, we move onto contrast. This was much as expected from the panel used. The static contrast was decent, whilst there was no ‘IPS glow’ or anything of that nature to worry about. The monitor was therefore able to do a decent job at creating reasonably atmospheric dark scenes. There was some artificial detail enhancement going on that is very common indeed on all models that use this specific panel, though, which sapped this atmosphere a bit in places by revealing unintended detail.

When it came to the responsiveness the news was certainly better – but not perfect. The monitor was able to provide a good fluid experience at high frame rates, thanks to its 144Hz refresh rate. The pixel overdrive implementation was a bit flaky. It generally worked well at higher refresh rates, with only minor and rather inconspicuous overshoot and no conspicuous conventional trailing using the right ‘Overdrive’ setting. Meanwhile the very low input lag and simply the high refresh rate itself gave a really nice ‘connected feel’ to gaming that competitive gamers in particular will love. At lower refresh rates (60Hz for example) the overshoot became more conspicuous. Not to horrendous levels that will make users want to claw their own eyes out, but certainly to a level that is more noticeable than at high refresh rates. And this persisted regardless of the ‘Overdrive’ setting – unless of course you turned it off entirely, which then produced significantly conventional trailing instead.

The saving grace for this monitor and indeed its major selling point is the inclusion of AMD FreeSync variable refresh rate technology. We can’t deny that this was a significant bonus that improved the playability massively in those common situations where frame rate starts to fall below the refresh rate of the monitor. What this technology does not do is make low frame rates feel like frame rates – you need the highest possible frame rates to benefit most from reduced motion blur and the ‘connected feel’ when gaming. But it’s certainly nice not having the experience interrupted by the usual stuttering or tearing that accompanies refresh rate and frame rate mismatches, right the way down to 35Hz. The aforementioned issue with overshoot at lower refresh rates also came into play with FreeSync enabled, as the monitor uses those lower refresh rates dynamically when the frame rate creeps down. We still feel that having FreeSync enabled is of great benefit, overall, which outweighs this imperfect overdrive implementation.

The bottom line; this monitor has its fair share of problems. But it is a fairly inexpensive entry into the world of FreeSync that provides a fluid and generally enjoyable gaming experience.