Viewing Angles, Uniformity, Response And Lag
To learn how we measure screen uniformity, please click here.
This is a fairly typical result for any TN panel but if you look closely you'll see a little more shadow detail in the side-angle view. Most monitors we photograph can't distinguish the bottom two brightness steps. There is also an obvious color shift to red and green but again, it's not quite as severe as other TN panels we've worked with. From the top, there is significant loss of detail from a gamma shift. In the head-on viewing position however, we'd say it's a little easier to position the U2879VF than other Ultra HD TN screens.
Screen Uniformity: Luminance
We ran our uniformity tests with and without compensation and found only a small measureable, and no visible difference. This is a high-quality panel that doesn't need any help to look good. Our sample had no light-bleed or hotspots whatsoever.
Here's the white field measurement.
AOC hasn't engineered any appreciable compensation into the brighter end of the scale. Not only is there no real change in uniformity, output is almost exactly the same too. While we applaud AOC's attention to detail, we wouldn't call this a defining feature of the U2879VF.
Screen Uniformity: Color
Color uniformity is similarly unaffected. We couldn't see a difference and apparently our i1Pro barely could either. We have absolutely no complaints with our sample. It provides an excellent picture regardless of application.
Pixel Response And Input Lag
Please click here to read up on our pixel response and input lag testing procedures.
Here's where the gaming monitor designation gets a bit fuzzy. AOC mentions the professional credibility of the U2879VF in its marketing and backs it up with calibration data and great color performance. But the inclusion of FreeSync will naturally appeal to gamers. In our response test however, we recorded performance more on par with a general-use screen. The Acer XB280HK, which uses the same panel, can draw a frame in only 14ms at the same 60Hz. While this may not seem like a huge difference, it does have a perceptible effect on motion blur. The AOC has just a little more. Overdrive will improve motion resolution a little but we would like to see faster response from a gaming display.
Here are the lag results.
Input lag is disappointing at 87ms. While casual players won't regret purchasing the U2879VF, those with fast reflexes may find themselves at a disadvantage. For sheer speed and the best use of a 60Hz refresh rate, the Acer XB280HK is still the top choice for Ultra HD gaming, albeit a more expensive one thanks to G-Sync.
Gaming With FreeSync
After recording less-than-stellar response and lag numbers, we were anxious to try the AOC under real-world conditions. Ultra HD gaming is a challenge after all, especially with our Radeon R9 285-equipped testbed. Its performance is not really sufficient to drive eight-plus mega-pixels with speed but if detail levels are lowered, we can achieve playable framerates. We started with overdrive maxed and detail adjusted to keep us inside the FreeSync operating range of 40-60Hz.
Battlefield 4 is our least-demanding title and can be played comfortably at 50-60fps in high detail mode. We found the overdrive sweet spot to be at the medium setting. Strong causes too much ghosting and weaker options expose obvious motion blur. This is where a higher refresh rate would really be welcome. We saw no ill effects from the U2879VF's panel response but there was a barely perceptible sense of input lag. It didn't affect our ability to play the game but when the mouse was moved rapidly we could see a tiny delay. Highly-skilled gamers will likely want a more responsive screen. Honestly, we're not sure any Ultra HD monitor is quite ready for the rigors of serious competition.
As with any FreeSync display, keeping the fps count above the minimum (in this case 40) is key. Lower numbers mean excessive judder and lag as V-Sync takes over. There won't be any tearing but gameplay takes a serious dive in quality. And the U2879VF doesn't qualify for low-framerate compensation with its narrow operating range.
In the Ultra HD gaming category, this isn't our favorite but it is adequate for casual play. Overdrive works reasonably well and input lag will only be an issue for the more-competent player.
