Blur Busters Forums

HI All,

Input lag for the most part is the only factor I really care about when coming to a gaming monitor. Everyone knows the VG248QE is one of the fastest gaming monitors around, but I wanted to upgrade to a 27" @ 2k w/ at least 144hz. I read a lot of good things about the Dell S2716DG in regards to input lag (TFTCENTRAL States 4.25ms total lag) and came across a great deal so I picked one up.

I wanted to do an input lag test of my own to really see what the difference would be between two monitors so I set them both up in clone mode @ 144hz and started snapping pictures. I only have my cell phone available atm (Galaxy s7 EDGE). At first all the results were identical, so I lowered my shutter speed down to 1/240000, and the mass majority of results were identical except for a few here and there showing a 10ms difference between the two (The dell showing less milliseconds, the asus showing more (Faster)).

What does this mean exactly? Is the Dell S2716DG basically the same speed in regards to input lag or is it noticeably slower? I'm not convinced the Dell S2716DG is as fast as my asus but I can't be sure by only playing pubg and arena shooters and doing the 'feel' test. I fear the Dell is 10ms slower than my asus and if that's the case I'd return the dell right away.

Any thoughts on this?

Any recommendations on the absolute fastest 27" 2k monitor, etc?

I thank you all in advance!

T

Cell cameras have several major problems in input lag benchmarking:

(1) Cell phone camera sensor scanning. Most scan their sensors top-to-bottom.
Workaround: Always photograph in landscape mode while standing far away from monitors, with the two screens exactly side by side, so it consumes only 1/10 height of photograph ideally. A slow-scanning camera sensor that takes 1/60sec to scan the sensor from top to bottom, only takes 1/600sec to scan one-tenth the height of the photograph, greatly improving results. This reduces camera sensor scan interference

(2) Cell phone camera exposure length. Most are too long exposure
Workaround: Use a very fast exposure speed.

There is still however, refresh cycle quantization (rounding-off errors) when doing smartphone benchmarking. So if 80% of photographs are exactly identical and 20% of photographs are 1 refresh cycle apart (e.g. 1/120sec) -- if you average the data, then that may mean you only have 20% of a refresh cycle lag. Meaning if 1 out of 5 show a 10ms difference, that usually means only a 2ms difference between the two. However, this is not a hard-and-fast rule, and makes some several assumptions about camera sensor scan direction and exposure length. But assuming that is kept under strict control, with smart knowledge of how camera sensors work, then you can simply average dozens of runs to get a reasonable subframe estimate of differential input lag between two monitors. However, it is easy for error margins to overwhelm.

Hey Chief,

Thank you for taking the time to respond! Much appreciated .

The information regarding cell phone cameras was definitely helpful. I jacked up the ISO and increased the shutterspeed to something ridiculous like 1/250000 and did notice a 10-20ms difference every so often but I'm just not happy with the results. The good news however, I found my DSLR (D300), so I plan to test again with this bad boy and compare.

don't trust clone mode