Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync
Posted: 29 Mar 2018, 07:18
Thanks for you reply, I have also other few questions: did you tried also the 2200 HT @240hz? Are you on win 7 or win 10? could you please also read the "stats" in latencyMon to see the average and maximum values, please?k2viper wrote:I dont have other monitors to compare it side by side with LG, and dont have an instruments to measure input lag.giubox360 wrote:When you finish the test, please tell us more about the real "input lag" on the LG @240 hz
For me LG's 240hz is absolutely fine, rapidly fast, good "connected feel".
System DPC latency measured at 60hz, has definitely lower minimums then at 120, 144, 240hz. I looked at the timings sets of these resolutions and see, that 60hz has 2200 HT, 120-144hz has 2080 HT and then 240hz has 2040 HT.
I only can suppose that Nvidia driver may be working "better" with higher HT like 2200 and struggling to work with HT 2040.
Most others 240hz monitors resolutions that I saw, used HT 2080 at 240hz.
But still, even if I can measure system DPC latentcy differences at 60hz vs 240hz, that difference is not so prior.
On my system, I'm getting like 25-30 microsecond "average" and about 70-80 max at idle.
If I set 60hz, I can sometimes see a one digit "minimum" numbers like 4-9 microseconds. At 120-144hz minimums were about 18-19. At 240hz they are about 22-23.
In A Solid lad's video there is the same thing, minimums go lower but averages are still about the same when he choose 60hz.
It's just 0,01-0,02 ms DPC delay difference with no additional high spikes.
My opinion is that the slugginess A Solid lad mentioned, is not an additional DPC latency related (since an additional 0,01ms is really not much), but likely Nvidia GPU scaling related. Because if GPU scaling on Nvidia Pascal GPUs are used, it should be line-by-line unbuffered scanout processing, AFAIR Chief explained that. And thus, different resolution timings set can possibly affect how that scaling is processed.
So, I think it's possible that there will be no actual difference if user will not use GPU scaling. Anyway, we need an instrumental measurements to clear this out.