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 » 22 Aug 2018, 13:21

RealNC wrote:So let me get this straight: when using 1080p, which should just always use the same path through the scaler since it's the native res, doesn't use the same path and is tied to the scaling option selected in the OSD?

That's just not right. Somebody screwed up at LG :-/
Yes this is dumb, since 1920x1080 is a native res and shouldnt be scaled at all, but for some reason, one out of three aspect modes in OSD, results as "true direct" and two others are buffered.
I dont see a reason why that was made, I was supposing that Original mode may be somehow related to advertised on LG's site "Dynamic action sync" and e.g. enables that hidden feature due to dedication of Original mode to CS 4:3 resolution gamers.

But, DAS shouldnt work along with the strobing (again, according to LG's site), but in Original mode measured input lag decreases regardless if strobing is on/off. So I think its just an "true direct" mode without any buffering, thats also why it shows yourself more stable in raised VT operation, then buffered modes.
It also may be that Original is just a wrong name and it was supposed to be named more straight.

Also, its clear that LG uses an Mstar scaler just like many others, its an Mstar having different paths for 1080p which are tied to some OSD-controllable options, not LG. E.g. Benq implement that direct path with their "instant mode", when LG hides their advertised DAS mode and ties direct path to another OSD option. There'll be not such a case, if Mstar scalers and firmwares didnt have different paths for a native res signals. But sure, LG's implementation is unclear for users and reviewers.

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saw141
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by saw141 » 26 Aug 2018, 10:29

Has anyone got to try the 27” BenQ XL2740? How is it? Does it matter that it doesn’t have “DayAc” like the XL2546? I’m really pining for more info about it’s performance after selling my XL2720, I want 27” 240hz but I don’t know which will be the best for me. I really only care about clarity and speed, but would still like 27” , colors don’t matter too much to me.

I saw on the Blurbusters BenQ strobe utility that the XL2740 doesn’t work with it; someone explained to me it’s because it single strobes everything past 120? I think...it apparently “double strobes” at some levels? I’m new to the intricacies of monitor technology at these performance levels and am trying to educate myself; However, information about the XL2740 is so scare, even here. Sorry to bring up a different monitor, I just think a 27” discussion is a good place.

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

Post by A Solid lad » 27 Aug 2018, 12:27

saw141 wrote:Has anyone got to try the 27” BenQ XL2740? How is it? Does it matter that it doesn’t have “DayAc” like the XL2546? I’m really pining for more info about it’s performance after selling my XL2720, I want 27” 240hz but I don’t know which will be the best for me. I really only care about clarity and speed, but would still like 27” , colors don’t matter too much to me.

I saw on the Blurbusters BenQ strobe utility that the XL2740 doesn’t work with it; someone explained to me it’s because it single strobes everything past 120? I think...it apparently “double strobes” at some levels? I’m new to the intricacies of monitor technology at these performance levels and am trying to educate myself; However, information about the XL2740 is so scare, even here. Sorry to bring up a different monitor, I just think a 27” discussion is a good place.
There's actaually a hefty load of info abouit it, even in this thread, just scattered around... use the search option.

Here's a list of all the posts on this forum, in which the xl2740 is mentioned:
search.php?keywords=xl2740&terms=all&au ... mit=Search

Happy hunting ;)
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saw141
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by saw141 » 27 Aug 2018, 22:28

A Solid lad wrote:
saw141 wrote:Has anyone got to try the 27” BenQ XL2740? How is it? Does it matter that it doesn’t have “DayAc” like the XL2546? I’m really pining for more info about it’s performance after selling my XL2720, I want 27” 240hz but I don’t know which will be the best for me. I really only care about clarity and speed, but would still like 27” , colors don’t matter too much to me.

I saw on the Blurbusters BenQ strobe utility that the XL2740 doesn’t work with it; someone explained to me it’s because it single strobes everything past 120? I think...it apparently “double strobes” at some levels? I’m new to the intricacies of monitor technology at these performance levels and am trying to educate myself; However, information about the XL2740 is so scare, even here. Sorry to bring up a different monitor, I just think a 27” discussion is a good place.
There's actaually a hefty load of info abouit it, even in this thread, just scattered around... use the search option.

Here's a list of all the posts on this forum, in which the xl2740 is mentioned:
search.php?keywords=xl2740&terms=all&au ... mit=Search

Happy hunting ;)
Thank you, I will read everything in these threads but just mentions doesn't necessarily mean there will be new info or details I'm looking for, I don't mean to sound rude. I greatly appreciate all the help :)

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

Post by A Solid lad » 28 Aug 2018, 12:17

saw141 wrote:just mentions doesn't necessarily mean there will be new info or details I'm looking for
IKR mate, ikr.
I know how much of a pain in the ass will it be to go thru all those threads, while being fully aware of that fact.
I know, because I did the same a couple of moths ago. :P

...

Before realising that I still don't know enough, and that I need to buy the monitor to see everything for myself. :D
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zbone
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by zbone » 25 Sep 2018, 23:47

Got this one in yesterday and it's spent first few hours side by side with XB271HU.

Expectations and why I bought it:
- to reduce motion blur in Overwatch compared to the IPS panel without sacrifice in FPS (ULMB limits output to 120Hz on XB271HU) and, hopefully, without colors deterioration making target recognition difficult, that is also present in ULMB mode

First impressions:
- Colors with LG Blur Reduction mode ON and FASTER mode are just as terrible as on the IPS panel in ULMB mode with brightness cranked up. The only difference is perceived dynamic range makes it tolerable and usable in both bright and dark locations, which is not the case for XB271HU. What was unexpected is in BR mode you can't adjust colors at all.
- XB271HU ULMB produces noticeably clearer image than LG BR, based on my perception. However, LG BR is actually bright, which makes it more usable across all scenarios. I would compare LG BR performance to XB271HU Overdrive set to Extreme in terms of performance but without all the halo effects that go hand to hand with in OD mode.
- It is VERY grainy looking 1080p with 100% scaling comparing to 1440p with 75%. I did expect it to be a rough change though.
- With VSYNC OFF, which is my default, despite running over 260fps I can see noticeable inconsistent jerkiness when moving the mouse. I tried limiting fps to 240, 241, 242 and 300 with 241 producing the best result, but the effect is still there and it's my biggest annoyance.
- During team fights it's now easier to understand what's going on (I never used XB271HU with ULMB on, used OD set to Extreme instead), but my aim went to shit for unknown reason.

If anyone can suggest how to get rid of the jerkiness or improve on the blur reduction, that would be greatly appreciated.

Overall, it feels more of a sidegrade rather than an upgrade and in that sense I feel somewhat disappointed. This monitor definitely goes to my kids' PC as soon as next gen 0.5ms panels are out.

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

Post by k2viper » 26 Sep 2018, 04:10

zbone wrote: What was unexpected is in BR mode you can't adjust colors at all.
Uhm.. RGB colors and gamma are fully adjustable in 1ms MBR mode. Perhaps you turned on one of the FPS/RTS gaming profiles, only profiles Gamer 1 and Gamer 2 are fully adjustable.
zbone wrote:If anyone can suggest how to get rid of the jerkiness or improve on the blur reduction, that would be greatly appreciated.
VT1304 tweak

Image

Jerkiness - inst it a case viewtopic.php?p=31262#p31262 ?
If yes, here is the solution I found viewtopic.php?p=31495#p31495

In my case its perfectly butter smooth in Overwatch with 300fps avg. No any visible inconsistence in framerate/refreshrate. I'm stuck to this VT1304 mode from the screenshot above for a 7 months or so. The only slight downside of this tweaked VT1304 res, is once a 3-5
days looks like it loses DP sync and starts go blackscreen and back on, but its easily cured by simple powercycling. Though, this is an overclocked resolution, its not a subject to complain about.

Also make sure you choose "Original" scaling mode, not default Full wide mode. "Original" has lowest input lag, there were some posts on previous 3-4 pages about that.
zbone wrote:XB271HU ULMB produces noticeably clearer image than LG BR, based on my perception
Very strange since LG's MBR has 1,17ms strobe persistence and its GtG is enough to clear most transitions during 3ms backlight off time.
For sure, crosstalk exists but its definitely tolerable, I doubt that IPS in XB271HU has same or lower GtG then TN.
I'm speaking of full 240hz strobed mode.

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

Post by RealNC » 26 Sep 2018, 09:59

zbone wrote:- XB271HU ULMB produces noticeably clearer image than LG BR, based on my perception.
You should try 120Hz BR on the LG, just as a test.
- With VSYNC OFF, which is my default, despite running over 260fps I can see noticeable inconsistent jerkiness when moving the mouse. I tried limiting fps to 240, 241, 242 and 300 with 241 producing the best result, but the effect is still there and it's my biggest annoyance.
You should try the low-lag VSYNC setup. At 240Hz, I would imagine this method actually working very well due to the very low frame time. RTSS should be accurate enough to do this.
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sdx
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Re: LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

Post by sdx » 27 Sep 2018, 17:04

So I tried to read through as much of the 34 pages of info on this monitor as I could.

Here's my summary and questions for clarification:
1) Strobing only works at 120hz, 144hz, 240hz. No other custom resolutions will work. No 180hz, no 200hz strobing?
2) *Edit - Input lag on "Original Mode" is very low.
3) Are there frame skipping issues on any default settings?

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

Post by k2viper » 28 Sep 2018, 04:01

1. Yes. I wasnt able to get strobing work in custom refreshrates as 180 and 200hz. It just doesnt strobe, only shows in OSD that 1ms MBR is on. Maybe some special custom timings are needed.

2. We found that in Original mode, input lag decreases for a one full frame, 4,17ms in case of 240hz. Original renders to be "direct" mode while default Full wide and 1:1 have that 1 frame buffering. TFTCentral's measurements was 8,75ms of total input lag in 1:1, so if we minus 4,17 it should become around 4,6 of total lag, that is on par or even better then other 240hz monitors tested by TFTCentral. So yes, it took time to find this, but monitor is not worse then others in terms of input lag.

3. There may be juddering issue that may be related to frameskipping, but it has a fix. In my case there is no any frameskipping since I'm using custom res with VT tweak and correct refreshrate. Also it may be already fixed in newer firmwares - e.g. my piece have fw 3.06 (according to service menu), and other user's piece have 3.07 and prod.date in may 2018, and he havent reported any juddering issues.

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