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!
User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

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

Post by Chief Blur Buster » 21 Mar 2018, 13:21

k2viper wrote:I think in 2019 we'll see new 27 240hz based on planned renewed AOU panels with reduced response time, there I hope it would be possible to achieve full 240hz CRT-like 1ms persistence.
This is a complex topic.
Persistence and strobe crosstalk are two separate benchmarks.
You can get 1ms persistence but terrible strobe crosstalk (double images).
Meaning super-sharp images but the images are doubled-up.

The ZOWIE XL2546 already does 0.25ms persistence at 240Hz (Blur Busters Strobe Utility -> Strobe Length -> reduce value). I've measured it myself, 0.25ms persistence is already here today with some compromises (1) Very dim picture, and (2) Strobe crosstalk

At 240Hz it is not fully able to fully hide LCD pixel transitions (GtG) in the blanking interval between refresh cycles.

We need faster scanout and/or faster pixel response, to reduce strobe crosstalk at 240Hz.
We need brighter backlights (and wider brightness adjustment range) so we lose less brightness during strobe mode.

So you are right, AUO could be the best improvement if what they are saying is true!

Long term --- Hopefully these new AUO panels will also be overclockable to 480Hz too -- any panel capable of 0.5ms LCD GtG is something we need for 480Hz operation. Do not believe the manufacturers when they say 480Hz is not important, it is important to keep pushing the Hertz higher, to eventually achieve blurless sample-and-hold (strobeless ULMB, strobeless blur reduction). Achieving 1ms CRT quality with zero flicker / zero strobing requires 1000fps at 1000Hz. (persistence equals frame time on sample-and-hold). -- It will take time -- especially it will also require GPU breakthroughs coming in the future, so I predict 2025 for 1000Hz gaming monitors -- but the journey to true 1000Hz is definitely worthwhile!
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

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

Post by Chief Blur Buster » 21 Mar 2018, 14:47

Some people have asked me (often) about GtG and MPRT:

MPRT is a millisecond number. (a motion response time benchmark)
GtG is a millisecond number. (a pixel response time benchmark)
MPRT and GtG are different response benchmarks. MPRT is more representative of motion blur.
MPRT is same thing as persistence (motion blur)
MPRT is not the same thing as a switchable motion blur reduction feature. However, MPRT changes when you enable/disable blur reduction.
GtG doesn't change when you enable/disable strobing.
MPRT does indeed change when you enable/disable strobing.
MPRT number is low for Blur Reduction ON.
MPRT number is high for Blur Reduction OFF.
Low MPRT numbers usually means they turned on blur reduction during the MPRT benchmark.

Manufacturers have been making things very confusing by quoting either MPRT or GtG millisecond numbers, or not even mentioning if their response benchmark is MPRT or GtG.

Many monitors allow you to turn on/off blur reduction.

However when you see "1ms MPRT", that usually means they turned on blur reduction in order to get number that low. Even 1ms GtG monitors can have 16ms MPRT in non-strobed mode. But when you enable strobing, it can fall to "1ms GtG, 2ms MPRT" or "1ms GtG, 1ms MPRT". GtG and MPRT can be two totally different numbers. GtG usually doesn't change, but MPRT does change dramatically when you turn on/off blur reduction mode.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

giubox360
Posts: 24
Joined: 15 Mar 2018, 11:18

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

Post by giubox360 » 22 Mar 2018, 16:41

@chief Blur Buster Did you received the new LG at 240hz to test it?

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

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

Post by k2viper » 23 Mar 2018, 08:44

A Solid lad wrote:I've ordered this monitor and it has arrived a couple of hours ago...but I have to wait for the night to arrive, so that I could take it home from work and try it.
Sooo? :)
You got it up and running?

User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

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

Post by Chief Blur Buster » 23 Mar 2018, 12:03

giubox360 wrote:@chief Blur Buster Did you received the new LG at 240hz to test it?
I have a few 240Hz enroute for tests, but LG isn't currently one of them (at the moment).
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

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 » 27 Mar 2018, 10:30

k2viper wrote:
A Solid lad wrote:I've ordered this monitor and it has arrived a couple of hours ago...but I have to wait for the night to arrive, so that I could take it home from work and try it.
Sooo? :)
You got it up and running?
Yes, but I'm not so happy with it as I hoped I would be. (Sorry for the late reply... been busy and had a lot of fun lately...visited Budapest for example to be at the "V4 Future Sports Festival" ...It was awesome, I got to meet and shake hands with two people whom I'd regard as legends in their own right.)
Anyway, I'm planning to do a similar video on the LG as I did on the other two 240hz monitors I've tried.
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 » 27 Mar 2018, 11:25

Hmm, what's wrong with it?

giubox360
Posts: 24
Joined: 15 Mar 2018, 11:18

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

Post by giubox360 » 28 Mar 2018, 06:30

@a solid lad
Do you prefer the alienware 240 hz freesync more than the new Lg with the Motion blur reduction?

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 » 28 Mar 2018, 08:39

giubox360 wrote:@a solid lad
Do you prefer the alienware 240 hz freesync more than the new Lg with the Motion blur reduction?
Yes, I do prefer it.

Here's a video I just made, in which I explain my problem with the LG:
phpBB [video]
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 » 28 Mar 2018, 09:58

Aaargh... just made a post and connection error lost it to me :(

In short, can you please use LatencyMon from resplendence, nowadays afaik its the only valid tool to measure DPC latency.

Also you should try reset-all.exe from CRU since last time you're having "a lot" of different monitors, just to make sure that nothing interferes wrong with Nvidia drivers.
Feeling of worse responsiveness also could be a mind trick, smaller size picture will always feel more rapid. I mean that 24" could produce feeling of better responsiveness, when set next to 27".

DPC latency though is a complex thing and personally I hardly beleive that one-digit-microsecond (1/1,000 of a millisecond) can produce felt by a human difference. But I'm aware that growth of DPC latency can indicate system low level problems, usually caused by drivers.
That's a strange since actually monitors do not use drivers apart from GPU (Nvidia in your and mine case). I'm really sceptic that other monitor can produce higher (or lower) DPC latency.
In my case, DPC latency havent changed when I switched to LG from VG278H.

That's how it looks like on my system (measured at idle)

Image
Last edited by k2viper on 28 Mar 2018, 10:15, edited 1 time in total.

Post Reply