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

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daniloberserk
Posts: 37
Joined: 22 Aug 2017, 16:50

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

Post by daniloberserk » 28 Nov 2018, 17:46

Hmm, apparently when I try the VT1034 trick, my 240Hz option disappear. I'm using the D-Port cable from the box and I have an R9 390x. Also, I applied the "patcher". Any ideas?

K, 1182 did the trick, it seems fine but my browser stutters a lot. I have a Xperia XZ premium wich can record high FPS footage. How can I test if my frame is skipping?

Also.. Freesync is showing as not supported on my AMD settings... Dport 1.2 is enabled, freesync on the OSD of LG is enabled. R9 390x, last driver.

Edit2: refreshrate on CRU show another value in comparison with the AMD driver.
refreshrate.png
refreshrate.png (232.61 KiB) Viewed 5558 times
Edit3:

Did some tests before the vtotal trick:
https://youtu.be/KHXXSMw7U6M
https://youtu.be/4_SFGJcBqRI

And after:
https://youtu.be/MhHMRqoa49s
https://youtu.be/ucOh3IrngTE


Also some pics with the "fast" setting, with mbr and without
with mbr.jpeg
with mbr.jpeg (119.14 KiB) Viewed 5555 times
sem mbr.jpeg
sem mbr.jpeg (60.69 KiB) Viewed 5555 times
Still no freesync...
Last edited by daniloberserk on 28 Nov 2018, 22:08, edited 1 time in total.

yehaw
Posts: 107
Joined: 21 Dec 2017, 21:41

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

Post by yehaw » 28 Nov 2018, 21:56

Got mine today and it's really nice, but it feels like mouse movement feels a bit delayed? I tried the faster overdrives, settings 1:1 and original aspect, but my mouse just feels a bit behind my actual movements. Like when I do a 180 turn really fast to check my flank, my hand stops when I complete the 180, but the turn takes a few ms to finish on screen.

Are there any other tweaks that need to be done for 240hz? Are the VT tweaks required if we're not using strobing?

daniloberserk
Posts: 37
Joined: 22 Aug 2017, 16:50

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

Post by daniloberserk » 29 Nov 2018, 00:18

K, little update, freesync is working now, had to clean install the drivers (with the AMD Crimson installer worked fine). So far so good! Freesync is awesome, but I think I still like MBR more, everybody is different after all.

yehaw
Posts: 107
Joined: 21 Dec 2017, 21:41

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

Post by yehaw » 29 Nov 2018, 10:08

I think I discovered why the mouse feels so laggy to me. Apparently this monitor has 6-7ms of signal processing lag? :o

That's a really high amount compared to others and prob why the input feels so laggy compared to the Alienware 240hz I tried, which didn't even have 1ms of signal processing lag. No matter what settings I use, the mouse just feels floaty to me, even if I go back to my 165hz screen, the mouse feels more responsive on the 165hz screen. It almost feels like V-Sync is on for the LG display, as it has that same floaty feel, but it's not enabled.

Another thing with this monitor, it has some weird judder/stutter problem, even when my FPS is extremely stable. It's very apparent when I do the testufo sight and watch the aliens go by.

Also another weird bug, when you go into fullscreen game, sometimes it shows green garbled artifacts or something on the screen a few seconds. And lastly, it has a weird whining sound that is really annoying if you're in a quiet room. If I put my ear to the back of the panel, it's clearly coming from the monitor.

Image

Kheri
Posts: 59
Joined: 29 Sep 2018, 13:39

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

Post by Kheri » 29 Nov 2018, 20:19

yehaw wrote:I think I discovered why the mouse feels so laggy to me. Apparently this monitor has 6-7ms of signal processing lag? :o
Supposedly if you run in "original" mode (not 1:1) it takes a frame or 4ms off that "signal processing lag." A Solid Lad discovered how much lag it has, then someone else discovered the monitor doesn't run in native at 1920x1080 on 1:1 (I forget a lot of the details.) TFTcentral did their review in 1:1 mode IIRC.

So not sure why it feels laggy to you, but I don't think it's the supposed signal processing lag(?)
yehaw wrote: Another thing with this monitor, it has some weird judder/stutter problem, even when my FPS is extremely stable. It's very apparent when I do the testufo sight and watch the aliens go by.

Also another weird bug, when you go into fullscreen game, sometimes it shows green garbled artifacts or something on the screen a few seconds. And lastly, it has a weird whining sound that is really annoying if you're in a quiet room. If I put my ear to the back of the panel, it's clearly coming from the monitor.
It's possible your monitor is defective? Maybe the green artifacts could be due to switching to 8-bit color depth?

The stutter is consistent, right, and you have a green "ready" at 240hz? To get rid of the stutterer, I would suggest getting custom utility resolution program (CRU.exe) and setting the Vertical totals to 1304 (like in the first post of this thread) and refresh rate to 239.760hz, saving those settings, running restart.exe, and then checking on testUFO again. THEN switch MBR back off and on again, and see if the stutter is gone.

daniloberserk
Posts: 37
Joined: 22 Aug 2017, 16:50

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

Post by daniloberserk » 30 Nov 2018, 11:22

k guys, I don't know how "precise" this tests I made is but I hope it can help for something.
I have a Sony Xperia XZ premium, which can record 960fps for about 1/4sec. I made some comparisons with the LG 27GK750F and my Benq XL2420z

144 Hz on both displays, aspect: full wide on LG:
https://www.youtube.com/watch?v=zrCryMk ... e=youtu.be

144Hz on both displays, aspect: original on LG:
https://www.youtube.com/watch?v=MG_QGNM ... e=youtu.be

240Hz vs 144Hz, aspect: original on LG:
https://www.youtube.com/watch?v=vVgINau ... e=youtu.be

The Benq is connected via DVI-DL and the LG on d-port on my R9 390x.

I'm note sure how "precise" this test is but it seems the LG is slight slower on 144Hz, but faster on 240Hz. Fullwide x Original seems about the same for me...

Edit:

Two more tests...

Full Wide - 240Hz: https://www.youtube.com/watch?v=Dav8tR5 ... e=youtu.be
Original - 240Hz: https://www.youtube.com/watch?v=rC2oojz ... e=youtu.be

Again... I don't know if this can help or something... It seems strange, sometimes the LG is faster and other times, the Benq is faster?

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k2viper
Posts: 293
Joined: 23 Jan 2018, 06:30

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

Post by k2viper » 01 Dec 2018, 09:33

daniloberserk, where your 240hz option disappears when you apply vt1304? It should stay in place in windows screen properties. If it's not it may worth trying to apply it via AMD driver custom resolution panel. If still no luck, it may be some AMD graphics driver flaw. I've heard no reported issues with applying this trick on Nvidia GPUs.

yehaw, TFTCentral measured it in 1:1 and Full wide aspect modes (I directly asked them via email), but after all a forum user found and tested, that only Original scaling mode has lowest lag, it is one full frame lower then both Full wide and 1:1. I added it in TLDR post, make sure you use Original aspect mode. You also complain about stuttering/juddering, it has a solution. Read TLDR post in thread start.
Still, no any green or other colored artifacts on my unit, also no any coil whine. It is possible that your unit is defective.

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k2viper
Posts: 293
Joined: 23 Jan 2018, 06:30

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

Post by k2viper » 01 Dec 2018, 09:46

daniloberserk wrote:k guys, I don't know how "precise" this tests I made is but I hope it can help for something.
I have a Sony Xperia XZ premium, which can record 960fps for about 1/4sec. I made some comparisons with the LG 27GK750F and my Benq XL2420z

144 Hz on both displays, aspect: full wide on LG:
https://www.youtube.com/watch?v=zrCryMk ... e=youtu.be

144Hz on both displays, aspect: original on LG:
https://www.youtube.com/watch?v=MG_QGNM ... e=youtu.be

240Hz vs 144Hz, aspect: original on LG:
https://www.youtube.com/watch?v=vVgINau ... e=youtu.be

The Benq is connected via DVI-DL and the LG on d-port on my R9 390x.

I'm note sure how "precise" this test is but it seems the LG is slight slower on 144Hz, but faster on 240Hz. Fullwide x Original seems about the same for me...

Edit:

Two more tests...

Full Wide - 240Hz: https://www.youtube.com/watch?v=Dav8tR5 ... e=youtu.be
Original - 240Hz: https://www.youtube.com/watch?v=rC2oojz ... e=youtu.be

Again... I don't know if this can help or something... It seems strange, sometimes the LG is faster and other times, the Benq is faster?
Well, some notes on measuring technique:
Display cloning dont work well for this purpose, a clone source display should have about a frame less delay then cloned one. Use display panning.
Any browser based stopwatch timers are innacurate due to Vsync is forced in Windows and broswer. That's why browser-based measured results are always multiple to given frame time. It is innacurate but still can give an idea which mode is faster and which is slower.
You show in OSD that freesync is active. Disable it for display lag measuring purpose.

yehaw
Posts: 107
Joined: 21 Dec 2017, 21:41

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

Post by yehaw » 01 Dec 2018, 12:49

Pretty funny, but for some reason, when I got my monitor, it didn't auto-detect properly. I had to manually set the resolution to native and set 240hz. After that, I had a system update scheduled to restart. After restarting, apparently NVCP was reset to 144hz. So the reason why it felt laggy, was because my refresh rate was reset to 144hz. :lol:

As far as fixing the weird stutter I see, I tried the CRU settings detailed and then using the restart file, but it just loses signal after I apply it? I had to round up the refresh rate, as mentioned in the guide. I restart my PC and it gets back into windows and displays picture. If I go back to CRU, it shows the value of 239.760hz that I changed to, but I'm unsure if it's actually applied or not? I can still see a weird judder panning back and forth in games. It almost looks like a FPS hiccup, but my FPS is stable 300+. Image of settings I tried.

And can anyone else that owns this monitor confirm if there is a hissing coming from the circular vents on the back? I'm not sure if I'm sensitive to the frequency of this sound, but it's been driving me mad, as I have a near silent PC. I tried different power plugs and strips, tried messing around with brightness, but can't get this dam noise to go away.

Other than these issues, I'm really impressed with it. The coating is very acceptable, text and images look sharp, the colors have some pop, and my favorite thing - great uniformity and probably the best backlight I've ever owned, as it's the least amount of bleed I've ever seen for any monitor. The stand is also very nice, I just wish it went a bit lower.

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k2viper
Posts: 293
Joined: 23 Jan 2018, 06:30

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

Post by k2viper » 01 Dec 2018, 13:15

If CRU is displaying 239,760 you successfully applied the fix. As I see on the screenshot, settings are correct.
The known juddering/stuttering if refreshrate is not exact 239,760 is occuring once/0,5sec - once/1sec, if you're getting lower judder rate, probably I havent seen that kind of issue.

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