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Viewing Angles, Uniformity, Response, Lag And Gaming
To learn how we measure screen uniformity, please click here.
AHVA stands for Advanced Hyper-Viewing Angle and this photo shows why. There is almost no color shift or light falloff to the sides. All the steps are clearly visible and image quality is largely unchanged. There is a green shift and brightness reduction when looking down from the top but that issue is less-important in most situations. LCD panels don't really get better than this for off-angle viewing.
Screen Uniformity: Luminance
After the ANSI result, we were concerned the XB270HU's black field uniformity might suffer; but happily, that's not the case. The hotspots we measured in that test are not visible here. There is no light bleed or blotchiness apparent in our review sample.
Here's the white field measurement comparison.
The white field test is equally solid with a 10.69 percent result. Instruments show a slight center hotspot but our eyes just see a smooth-toned image. As you can see, the TN panels in today's group do not suffer any quality issues.
Screen Uniformity: Color
The color uniformity test is a tough one for any monitor and this time the XB270HU came out on top. The low number would have been even better if it weren't for a slight red shift (visible only to our i1Pro) at the bottom of the screen.
Pixel Response And Input Lag
Please click here to read up on our pixel response and input lag testing procedures.
To set the XB270HU to its fastest response mode, use a 144Hz refresh rate with overdrive on the Extreme setting. You can see the IPS technology gives nothing away to its TN counterparts. So the conclusion is that TN and IPS can be equal in speed but TN costs less to implement.
Here are the lag results.
Input lag is equally excellent at a brief 28 milliseconds. Again, it's hard to say that TN has a clear advantage in performance.
G-Sync, ULMB And In-Game Testing
After enabling G-Sync and setting the refresh rate to 144Hz, we tried out Far Cry 4, Tomb Raider and Battlefield 4. Far Cry 4 places greater demands on the graphics hardware so it was easier to see the effects of G-Sync, ULMB and overdrive options on gameplay. If you're debating between G-Sync and ULMB, go with G-Sync. There's no motion blur to speak of, even when frame rates drop into the 60s. And once you get below 35fps the judder becomes more apparent than the blur. Since G-Sync simply repeats frames below 30fps, you'll never see any tearing; but at that point, gaming that requires fast reflexes becomes difficult.
Thanks to our Titan X-equipped system, we were able to maintain rates over 100fps except in Far Cry 4 where they settled in the 70-80 range at the Ultra detail setting. The extra speed afforded by a fast-refresh screen like this definitely makes for a smoother experience. While we enjoyed gaming at 45-60fps on the Ultra HD XB280HK, higher rates do make a difference in clarity and overall feel.
While we're glad to see Acer include ULMB in this premium-priced product, we're not sure that anyone will want to give up G-Sync to use it. Of course that is a limitation that all G-Sync monitors share at present. Ultimately, the matched refresh rate is the single best reason to invest in a monitor like this. All the other features have far less impact on image quality.
