LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

[giubox360]

When you finish the test, please tell us more about the real "input lag" on the LG @240 hz

I dont have other monitors to compare it side by side with LG, and dont have an instruments to measure input lag.
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.

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]

I havent tried 2200 HT @ 240hz yet.
I'm on Windows 10 1709, but A Solid lad, as it seems from his video, is on Windows 7.

[A Solid lad]

Yip. (Returning the monitor in 1 hour....GOTTA GO FAST)

[giubox360]

I havent tried 2200 HT @ 240hz yet.
I'm on Windows 10 1709, but A Solid lad, as it seems from his video, is on Windows 7.

I just asked because I tried the new LG 240 hz yesterday, and I think colours and contrasts are very good for a TN panel.
This time LG did very good job with his motion blur reduction 1ms (but I still prefer the way Samsung do it in their 144hz panels)

DPC latency:

I'm on win 10 and I can say that dpc latency in the new LG 240 hz for me is about 5/10 ms more than my current monitor:
Samsung cfg70 144 hz with motion blur reduction active, (but on latencyMon's the STATS measure is around the same for the two panels: max 45 ms average 3,40 ms, but I don't know if trust that values more than the current values showed in the test.)

The LG has a minimum read of one digit in rare occasions around 5/9 ms and stay more on the 20 ms target at @240 hz (no VT tweeks)
The SAMSUNG sits way more time around 5/10 ms (and this is impressive considering both are working with motion blur reduction active.)
The samsung has black smearing (not so strong), but the crosstalk is less on the samsung that is more uniform in any part of the screen, if we forget about the little black smearing (I don't find them when playing games anyway.)
In particular the "street view" test is more clear on the Samsung monitor on "fastest "mode @144hz , but the ufo test is better on the LG.

Input Lag:

Testing input lag just with the Human reaction test, I probably would say the input lag is similar, maybe just 2-5 ms more for the LG panel, but I'm not sure.
I'm not sure also that these 240 hz are so needed when a good 144 hz with Ulmb/ lightboost or just like samsung already did a good job.
Anyway LG seems a very good panel, I have to test it more to decide if keep it or returning it.

p.s.
from my esperience I find 240 hz without motion blur reduction, less nice than 144 hz with blur reduction activated.
For this reason I tried the LG, and I'm curious if the Benq 2546 would be better or not with Dyac activated.

[A Solid lad]

I can't even get my PC with the LG monitor connected, to dip into single digits...
do u have HPET disabled of enabled?
I have it disabled in both windows and bios...
What about pagefile? I have that disabled as well...

p.s.: We're talking about microseconds, not milliseconds, when it comes to dpc latency testing.

[A Solid lad]

Here are some further findings of mine, in video form btw:

phpBB [video]

[k2viper]

I can't even get my PC with the LG monitor connected, to dip into single digits...
do u have HPET disabled of enabled?
I have it disabled in both windows and bios...
What about pagefile? I have that disabled as well...

p.s.: We're talking about microseconds, not milliseconds, when it comes to dpc latency testing.

In my case HPET is disabled in bios (Z270) and /deletevalue useplatformclock , which should force Windows to use TSC timer which is reportedly better for win10 workaround.
For win10 I found that the best combination which results in lowest DPC latency numbers.

And I'm getting single digit numbers with LG connected, but only if I switch it to 60hz mode. Minimums hover around 4-9microseconds.
For 120-144hz I'm getting 18-19 minimums.
And with VG278H in 120hz I also was getting those 18-19 as minimums and also used HT 2080 for 120hz, just like LG for 120 and 144hz.

Thats why I think the DPC latency case is caused by LG's 2040 HT for 240hz. Maybe tomorrow I will have time to try 2200 for 240hz.

[A Solid lad]

Thanks for the infos!

[k2viper]

From "Stats" page of LatencyMon.
See how low reported averages are both for 60hz and 240hz. The main page displays higher readings.
Btw I cant use Latency checker that you use, on my Win10 it shows completely irrelevant readings.
I think you should also start using LatencyMon, its a more powerful tool.

[giubox360]

From "Stats" page of LatencyMon.
See how low reported averages are both for 60hz and 240hz. The main page displays higher readings.
Btw I cant use Latency checker that you use, on my Win10 it shows completely irrelevant readings.
I think you should also start using LatencyMon, its a more powerful tool.

I will post also mine after dinner, I'm curious if trust the values on the main screen on the one showed in STATS.
Anyway I have single digit 5/6 ms with 240hz, but is more around 20/25 ms (if I use VT 1304 the values are 2 ms higher)
I have all C states active in bios,the only thing I have is 100 % as minimum CPU usage (instead of 5% ) on the power setting.
(or the values are a lot higher)
@a solid lad could you try also our program to see all the data together please?