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To compare the XG27UCS’s performance, I’ve rounded up a group of 4K screens in both 27 and 32-inch sizes. We have Cooler Master’s GP27U, BenQ’s EX321UX, AOC’s PD32M, Acer’s X32 and HP’s Omen 27k. They run at either 144 or 160 Hz.
Pixel Response and Input Lag
Click here to read up on our pixel response and input lag testing procedures.
One doesn’t typically buy a 4K gaming monitor for all-out speed, but the XG27UCS delivers on that count. Its 160 Hz refresh rate, if you can achieve it with your hardware, draws a full white field on the screen in 6ms. This alone would deliver reasonably smooth motion but not completely eliminate motion blur. The XG27UCS sets itself apart with a superb overdrive. There is almost no blur or artifacts when the overdrive is set to level 10. The traditional ELMB option is even smoother, erasing all signs of blur. Note that ELMB Sync also does this but with a significant reduction in brightness.
The XG27UCS does very well in the lag test with a 23ms score. This puts it on par with some QHD 240 Hz monitors. If quick control response is a priority for you, this monitor delivers.
Test Takeaway: For all-out competition, the XG27UCS might be a tad slower than the fastest 360 and 500 Hz monitors but its input lag isn’t far behind the best. 4K is not always the best way to achieve high frame rates, but the video processing here enables smoother operation than most UHD screens are capable of. ELMB Sync is a great way to have backlight strobing and Adaptive-Sync at the same time, something only a few other Asus monitors can do. But it sacrifices a lot of brightness in the process. My recommendation is to use traditional ELMB. That presents a super-smooth moving image, and the lack of AS isn’t a big deal if you can run 160fps. Bottom line: the XG27UCS has the best video processing and game performance in the LCD 4K category. Only a 240 Hz OLED will be smoother than this and you won’t be touching one of those for $460.
Viewing Angles
The XG27UCS’s off-axis image quality is solid when compared to other IPS monitors. The 45-degree side view shows a shift to red but no significant light output reduction. Gamma stays consistent so there is no loss of picture detail. The top view is better than most IPS panels can boast but still shows a 50% drop in brightness and a slight red/blue shift.
Screen Uniformity
To learn how we measure screen uniformity, click here.
These are all high-end monitors so there is no shame in the XG27UCS’s last place finish. 8.45% is still comfortably below the visible threshold. My sample had no bleed or glow and color remained even-toned from edge to edge in test patterns and in all types of content.
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