Skip to main content

HP ZR2740w Versus Asus PB278Q: QHD 27" Monitors, Tested

Results: Pixel Response And Input Lag

To perform these tests, we use a high-speed camera that shoots at 1,000 frames per second. Analyzing the video frame-by-frame allows us to observe the exact time it takes to go from a zero-percent signal to a 100% white field.

The pattern generator is placed at the base of each monitor so that our camera can capture the precise moment that the front-panel LED lights up, indicating a video signal is being received by the monitor. With this camera placement, we can easily see how long it takes to fully display a pattern after pressing the button on the generator’s remote. This testing methodology allows for accurate and repeatable results when comparing panels.

Both panels finish squarely in the middle of the pack for panel response time. It’s interesting to note that just because one monitor brand uses the same panel as another doesn’t necessarily mean that they will match in response metrics. For example, the Asus PB278Q draws a white field three milliseconds faster than the Samsung S27B970D, even though both monitors employ the same Samsung-made PLS part. The HP is only slightly behind at 26 milliseconds.

Now let’s check out the overall input lag numbers.

The AOC I2757FH retains the lead in our comparison of recently-tested IPS screens. While one might think that its lower 1920x1080 resolution is a factor, the other 1080p monitor on the chart, ViewSonic’s VX2770Smh, is slower than both the Samsung and ViewSonic 1440p panels. The two subjects of this review are at the back of the pack by a few milliseconds, but still well ahead of the Auria EQ276W. The deciding factor here is in the design of the monitor’s input circuit board. Each manufacturer uses its own PCB, and we’ve seen companies that modify screens like the Auria with high-performance boards that not only improve input lag, but also allow for higher refresh rates. As always, pursue such mods at your own risk!

Christian Eberle
Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors.