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

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k2viper
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by k2viper » 18 Mar 2018, 08:59

A Solid lad wrote:Viper, do you use the custom res with increased VT for non strobed operation as well?
If so, does it make any difference, compared to default?
VT tweaks usually dont make sense with non-strobed. I use the same res, just toggle strobing in OSD.

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k2viper
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by k2viper » 18 Mar 2018, 09:01

A Solid lad wrote:Could I force the GPU to upscale every lower resolution to 1080p, thus keeping the same timings by deleting every other res from the EDID with cru, other than the edited 1080p 240hz and the default 60hz one...in your opinion? (keeping the latter for safe mode) :mrgreen:
Well, I actually have no experience with scaling, always were using native res with no gpu/display scaling.
But I beleive it can be done.

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

Post by RealNC » 18 Mar 2018, 09:08

If you enable GPU scaling in the driver control panel, you shouldn't need to delete anything in CRU.

But you can always verify in the monitor's OSD. It always tells you what mode the GPU is actually setting the monitor to. If the monitor still reports 1920x1080@240Hz even though you've set a lower res in the game, GPU scaling took over.
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by A Solid lad » 18 Mar 2018, 09:10

k2viper wrote:
A Solid lad wrote:Viper, do you use the custom res with increased VT for non strobed operation as well?
If so, does it make any difference, compared to default?
VT tweaks usually dont make sense with non-strobed. I use the same res, just toggle strobing in OSD.
Actually, I remember Chief saying that a larger VT speeds up scanout time... meaning you could theoretically gain reductions in input lag when using something like 120hz with a larger VT. (If for some reason, you were forced to use 120hz.)
Provided your monitor can handle the higher VT...and 240hz monitors might be able to use double the standard VT at 120hz.
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by A Solid lad » 18 Mar 2018, 09:21

RealNC wrote:If you enable GPU scaling in the driver control panel, you shouldn't need to delete anything in CRU.

But you can always verify in the monitor's OSD. It always tells you what mode the GPU is actually setting the monitor to. If the monitor still reports 1920x1080@240Hz even though you've set a lower res in the game, GPU scaling took over.
Yep, I knew about that, but... I'm not sure how accurate that reading is... I know it works pretty accurately on my xl2411z, but I'm not sure about the LG, since they don't seem to be as focused on lower res scaling as Benq was/is.
(Benq knows their target audience...low res CS players, so they were focused on scaling on their XL monitors, ever since the first one...which I think was the xl2410T...)
Aaaaand, the fact that EVEN my xl2411z, displayed false numbers at times on that info screen, doesn't build my trust.

Don't misunderstand me, I'm not a Benq fanboy, in fact I'm avoiding their monitors by now, because I know their weaknesses, but I can't ignore what they did/do right either.
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k2viper
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by k2viper » 18 Mar 2018, 10:14

A Solid lad wrote:Actually, I remember Chief saying that a larger VT speeds up scanout time... meaning you could theoretically gain reductions in input lag when using something like 120hz with a larger VT. (If for some reason, you were forced to use 120hz.)
Provided your monitor can handle the higher VT...and 240hz monitors might be able to use double the standard VT at 120hz.
That LG can handle around 1580 max VT for both 120 and 144hz, that's maybe some firmware limitation or I just havent found appropriate timings. It gives black screen over 1580-1582 VT even when pixelclock is within max range. I also tried bigger VT's like 2000, 2400, 2600 - same.

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

Post by dogroll » 19 Mar 2018, 21:45

k2viper wrote:
dogroll wrote:The gamma (in mode 4) is also superior, requiring less adjustment hardware calibration.
Afair you have colorimeter, does Black stabilizer also affect gamma? What setting do you ended with?
Haven't touched the black stabilizer, but based on my experience with it in other monitors it affects gamma along with some other aspects of the image. I think it's a nonsense setting anyway and just leave it at 50. All I do before calibration is change the RGB gain sliders. I ended up with R51, G48, B49 (default is 50, 50, 50).

I clean installed latest AMD driver 18.3.3, and I still have the problem with the 240Hz resoution disappearing if I make a change to its timings in CRU. However, it doesn't disappear if I raise the timings only very slightly (from 1180 to 1181), which gives me a correct refresh rate of 239.760Hz instead of .759. No improvement to strobe crosstalk will be possible like this unfortunately, but it does allow me to fix that annoying bug with the judder when switching modes.

Upon further testing I can get it running at 1194 VT which also gives me a correct 239.760Hz. Any higher than that and I either get incorrect refresh rate, or go too high (~1220+) and 240Hz disappears again.

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

Post by RealNC » 19 Mar 2018, 21:52

dogroll wrote:Haven't touched the black stabilizer, but based on my experience with it in other monitors it affects gamma along with some other aspects of the image. I think it's a nonsense setting anyway and just leave it at 50.
It's a setting intended for CS:GO, to eliminate dark areas of the screen. It's actually intended to ruin the image, not to make it better.
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k2viper
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by k2viper » 20 Mar 2018, 05:31

dogroll wrote: Haven't touched the black stabilizer, but based on my experience with it in other monitors it affects gamma along with some other aspects of the image. I think it's a nonsense setting anyway and just leave it at 50. All I do before calibration is change the RGB gain sliders. I ended up with R51, G48, B49 (default is 50, 50, 50).
Thanks.
Well, at least I was right that exact 239,760hz is needed to fix that juddery behavior...

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

Post by BTRY B 529th FA BN » 20 Mar 2018, 21:49

Are there two different models of this monitor?

What is it's MPRT? Is that the same thing as Blur Reduction?

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