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

Everything about displays and monitors. 120Hz, 144Hz, 240Hz, 4K, 1440p, input lag, display shopping, monitor purchase decisions, compare, versus, debate, and more. Questions? Just ask!
dogroll
Posts: 36
Joined: 24 Aug 2017, 16:20

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

Post by dogroll » 17 Mar 2018, 17:35

k2viper wrote:Spyro, Chief says right - sometimes strobing is better in fast-paced games, sometimes not.

E.g. CSGO-like games have many fixed-gaze scenarios when player controls some area and there's not much movement and target tracking.
On the other side, games like Overwatch or QC (not duels) have many intended target tracking. I beleive strobing really helps to track targets, because its making target edges sharper and then more natural.
240hz strobing though, have much less perceptible downsides then 120/144hz due to higher stroberate: inputlag price for strobing typically is about 1/2 of the refresh cycle time (only about 2ms at 240hz), and flickering is much less visible due to higher stroberate.

A Solid lad, I ended up using VT1304 at 240hz, this mode makes exact 239,76hz on my system, its stable and I dont get a behavior dogroll mentioned earlier (juddering/stuttering after MBR toggling). Tweaking is easy, run CRU, go to extension block, find 1920x1080 with 239.759 and change only Vertical total to 1304. Save, reboot.
Also I recommend using 1:1 scaling mode, it's stated that no adjustments are made to the input signal in 1:1, so I think its the real "instant" or "direct" mode with lowest input lag.

Thats my timings

Image
I tried your exact settings from this image and my display doesn't like it. 240Hz option disappears from windows display settings with these settings.

Actually scratch that, any change to the 240hz resolution causes it to disappear from windows settings now, wonder what's wrong...

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

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

Post by k2viper » 18 Mar 2018, 05:48

dogroll wrote:Actually scratch that, any change to the 240hz resolution causes it to disappear from windows settings now, wonder what's wrong...
Did you tried "reset-all.exe" from CRU?
The only thing different are that you're on AMD gpu and I'm on nvidia. I think your case is not display related, but AMD drivers related... Dunno what to say. CRU tweaks perfectly working for me. Anyway you should be able to do custom resolutions through AMD drivers control panel.

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

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

Post by k2viper » 18 Mar 2018, 05:54

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?

User avatar
A Solid lad
Posts: 317
Joined: 17 Feb 2018, 08:07
Location: Slovakia
Contact:

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

Post by A Solid lad » 18 Mar 2018, 06:04

k2viper wrote:Spyro, Chief says right - sometimes strobing is better in fast-paced games, sometimes not.

E.g. CSGO-like games have many fixed-gaze scenarios when player controls some area and there's not much movement and target tracking.
On the other side, games like Overwatch or QC (not duels) have many intended target tracking. I beleive strobing really helps to track targets, because its making target edges sharper and then more natural.
240hz strobing though, have much less perceptible downsides then 120/144hz due to higher stroberate: inputlag price for strobing typically is about 1/2 of the refresh cycle time (only about 2ms at 240hz), and flickering is much less visible due to higher stroberate.

A Solid lad, I ended up using VT1304 at 240hz, this mode makes exact 239,76hz on my system, its stable and I dont get a behavior dogroll mentioned earlier (juddering/stuttering after MBR toggling). Tweaking is easy, run CRU, go to extension block, find 1920x1080 with 239.759 and change only Vertical total to 1304. Save, reboot.
Also I recommend using 1:1 scaling mode, it's stated that no adjustments are made to the input signal in 1:1, so I think its the real "instant" or "direct" mode with lowest input lag.

Thats my timings

Image
Thanks for the info.

Though I'd like to mention something... everybody seems to mostly write off CSGO as a game, where there's not much benefit of getting increased motion clarity, since most players use the crosshair-gaze technique... but I for one, do not.
I'm one of those oldschool players, who likes to track moving targets with their eyes on the screen, so reduced motion blur does help me quite a bit.
It's unfortunate, that I don't really fancy all the negatives, which come with strobing. (e.g. flicker, less saturated colors, reduced brightness, input lag.

One thing I'd like to ask:
If you edit the default 240hz timings and overwrite them, will the monitor use the same timings even in lower resolutions? (I like to switch my res around in games for the sake experimentation...)
Discord | Youtube | Twitch
Steam with a list of monitors & mice I've used/use.

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

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

Post by k2viper » 18 Mar 2018, 08:08

Soon you will have a chance to test strobing for yourself :)
A Solid lad wrote:If you edit the default 240hz timings and overwrite them, will the monitor use the same timings even in lower resolutions? (I like to switch my res around in games for the sake experimentation...)
Every res with its timings and refreshrate is edited separately. If you edit your main 1920x1080x240hz, other refreshrates and resolutions would not be affected.

User avatar
RealNC
Site Admin
Posts: 3743
Joined: 24 Dec 2013, 18:32
Contact:

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

Post by RealNC » 18 Mar 2018, 08:13

Only monitor-supported resolutions will stay unaffected, and even that is only true if GPU scaling is disabled.

If GPU scaling is enabled, or the resolution+refresh combination is not supported by the monitor, 1920x1080x240hz timings are used instead since that's what GPU scaling does.

For example, if you switch to 1280x720@240Hz, and there's no such mode in CRU (and most likely there isn't), then the only way for that to work is with GPU scaling, which will use your 1920x1080x240hz timings.
SteamGitHubStack Overflow
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.

User avatar
A Solid lad
Posts: 317
Joined: 17 Feb 2018, 08:07
Location: Slovakia
Contact:

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

Post by A Solid lad » 18 Mar 2018, 08:47

I would like to use GPU scaling in all cases possible as I know it doesn't add input latency. (as opposed to display scaling)

On my xl2411z, the GPU pushes out a 1920x1080 144hz signal, no matter what res I set ingame... I think it just upscales the selected res to 1080p and sends that to the monitor... which I'm fine with.
So I assumed the timings and all would stay the same in this case...
(would save me the hassle of creating other resolutions and trying to get strobing as good on them as I can, by adjusting VT/HT)

Just wanted to get confirmation, whether this'll be the case or not.

Could I force the GPU to do exactly this (upscale everything to 1080p, keeping the same timings) by deleting every other res from the EDID with cru, other than the edited 1080p 240hz and 60hz one? (keeping the latter for safe mode)

Looking forward to replies...please also correct any wrong assumptions I might have made.
Discord | Youtube | Twitch
Steam with a list of monitors & mice I've used/use.

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

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

Post by k2viper » 18 Mar 2018, 08:48

Display supports modes (from user's manual):

Image

User avatar
A Solid lad
Posts: 317
Joined: 17 Feb 2018, 08:07
Location: Slovakia
Contact:

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

Post by A Solid lad » 18 Mar 2018, 08:51

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?
Discord | Youtube | Twitch
Steam with a list of monitors & mice I've used/use.

User avatar
A Solid lad
Posts: 317
Joined: 17 Feb 2018, 08:07
Location: Slovakia
Contact:

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

Post by A Solid lad » 18 Mar 2018, 08:56

k2viper wrote:Display supports modes (from user's manual):

Image
Soooo.... 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: (sry for being pushy, and thanks for the pic, interesting info :lol: )
Discord | Youtube | Twitch
Steam with a list of monitors & mice I've used/use.

Post Reply