GSYNC vs CRT input lag?

Everything about latency. Tips, testing methods, mouse lag, display lag, game engine lag, network lag, whole input lag chain, VSYNC OFF vs VSYNC ON, and more! Input Lag Articles on Blur Busters.
baskinghobo
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Joined: 28 Feb 2014, 05:38

Re: GSYNC vs CRT input lag?

Post by baskinghobo » 27 Jul 2014, 01:29

Also does displayport have the possibility to reduce system latency lower than that of crt which is limited to vga? Is it possible to achieve these results now using CRU?

flood
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Joined: 21 Dec 2013, 01:25

Re: GSYNC vs CRT input lag?

Post by flood » 27 Jul 2014, 16:24


baskinghobo
Posts: 9
Joined: 28 Feb 2014, 05:38

Re: GSYNC vs CRT input lag?

Post by baskinghobo » 27 Jul 2014, 19:31

The reason i am so overkill with such small input lag numbers is because there are so many combinations in mouse, monitors, graphic drivers etc and these small values can end up having quite the noticeable effect. Off the top of my head i could tell you about mouse smoothing lag, prerendered frames lag, resolution scaling lag, mouse polling lag and 125fps vs 250fps lag. So if i understand correctly the VT1502 trick does not work with my xl2411t and to get the benefit of reduced input lag i need the z-series monitor? Because i am getting very grainy matrixy like screen when i use it on my xl2411t. Is it supposed to be like this?

I just find this interesting because i've seen people talk about how they can feel the difference in inpur lag between a crt and a low input lag monitor (like benq instant on) when it shouldn't really be humanly possible because it is only 1-2 ms difference as you have stated. One would think this would be attributed to the motion blur and the input lag sensation it can cause yet many pro gamers prefer lightboost off than lightboost on because of the increased input lag lightboost adds and even that is only around 2-5ms. I have two theories on this. Either 1. We are more sensitive to input lag than most people realize or 2. Motion blur is the reason we feel crt's have lower input lag than the very best lcd monitors. or maybe it is a combination of both

flood
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Joined: 21 Dec 2013, 01:25

Re: GSYNC vs CRT input lag?

Post by flood » 28 Jul 2014, 15:54

baskinghobo wrote:The reason i am so overkill with such small input lag numbers is because there are so many combinations in mouse, monitors, graphic drivers etc and these small values can end up having quite the noticeable effect.
except the largest values are
>the screen refresh period (inverse of refresh rate)
>the game frame rendering time.

these can easily add 10+ ms whereas a 1000hz mouse contributes ~1ms, a good lcd monitor adds ~2-3 ms. displayport vs vga? well I think that's pretty much up to the speed of your graphics card's ramdac, and I think it would be less than 1ms. so honestly, don't worry too much about it.

oh right I have a 60fps video of of my vg248qe(gsync modded) vs a fw900 crt. both at 1280x720,120hz, lcd on left, crt on right.
https://drive.google.com/file/d/0B5jyMD ... sp=sharing

if you look at the location of the tear-lines when I'm panning, you can tell that the crt is marginally ahead by 3ms or so...

Q83Ia7ta
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Joined: 18 Dec 2013, 09:29

Re: GSYNC vs CRT input lag?

Post by Q83Ia7ta » 28 Jul 2014, 17:41

flood wrote:
baskinghobo wrote:oh right I have a 60fps video of of my vg248qe(gsync modded) vs a fw900 crt. both at 1280x720,120hz, lcd on left, crt on right.
https://drive.google.com/file/d/0B5jyMD ... sp=sharing
1280x720 isn't native(optimal) resolution for vg248qe(gsync modded). scaling processing affects.
But thanks for sharing.

flood
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Joined: 21 Dec 2013, 01:25

Re: GSYNC vs CRT input lag?

Post by flood » 28 Jul 2014, 19:14

k i'll redo with 1920x1080 @60hz tonight

flood
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Joined: 21 Dec 2013, 01:25

Re: GSYNC vs CRT input lag?

Post by flood » 28 Jul 2014, 19:36

baskinghobo wrote: I just find this interesting because i've seen people talk about how they can feel the difference in inpur lag
well yea the lack of motion blur in crts make the screen feel much more connected when eye-tracking is involved.

for anyone who claims to feel the difference in input lag between X and Y, ask them whether they can feel the difference in input lag between the Windows cursor at the top of the screen vs. at the bottom of the screen. that's a difference of 16.7ms for 60hz refresh rate and 8.3ms for 120hz. Yet I've never seen anyone talk about it...

Q83Ia7ta
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Joined: 18 Dec 2013, 09:29

Re: GSYNC vs CRT input lag?

Post by Q83Ia7ta » 28 Jul 2014, 20:08

flood wrote:for anyone who claims to feel the difference in input lag between X and Y, ask them whether they can feel the difference in input lag between the Windows cursor at the top of the screen vs. at the bottom of the screen. that's a difference of 16.7ms for 60hz refresh rate and 8.3ms for 120hz. Yet I've never seen anyone talk about it...
Actually Chief Blur Buster measured ~3ms for top edge of screen, ~7ms for middle, ~11ms for bottom edge for 120Hz monitor with LightBoost OFF. And this 90% this result of Asus VG248QE or BenQ XL2411T or may be some 27" LightBoost models also from Asus or BenQ. It's clear if you look at the time of post.
http://forums.blurbusters.com/viewtopic.php?f=4&t=16

Chief Blur Buster measured with his own tool calibrated to CRT.
http://www.blurbusters.com/arduino-photodiode-scope/
http://www.blurbusters.com/sneak-previe ... lag-meter/

And this mouse movement test (the difference in input lag between the Windows cursor at the top of the screen vs. at the bottom of the screen) has nothing to do with real game test in my opinion.

flood
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Re: GSYNC vs CRT input lag?

Post by flood » 28 Jul 2014, 22:02

Q83Ia7ta wrote:
flood wrote:for anyone who claims to feel the difference in input lag between X and Y, ask them whether they can feel the difference in input lag between the Windows cursor at the top of the screen vs. at the bottom of the screen. that's a difference of 16.7ms for 60hz refresh rate and 8.3ms for 120hz. Yet I've never seen anyone talk about it...
Actually Chief Blur Buster measured ~3ms for top edge of screen, ~7ms for middle, ~11ms for bottom edge for 120Hz monitor with LightBoost OFF.
eh... not sure what you mean by "actually" because that exactly confirms what I said: 8.3ms difference for 120hz.

what I mean is
sometimes well-intentioned people make claims about feeling differences in input lag when actually they are just feeling the effects of confirmation bias. yet those same people don't even notice the difference in input lag between the cursor at the top and bottom of the screen.

For example if you see someone claiming "using displayport feels so much less laggy than hdmi", he would be claiming that he can feel ~1ms or so of input lag. if he can honestly notice that, surely he'd notice the 8ms difference in input lag between cursor @ top/bottom of screen.

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cosmitz
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Re: GSYNC vs CRT input lag?

Post by cosmitz » 31 Jul 2014, 12:46

I transition daily from my home CRT to my gaming laptop and secondary rig with a 120hz display at work as well as some fancy Mac displays. I have gamed and watched video on all of them. Even at home switching between a TN and a IPS monitor that are to the left/right of my CRT i can tell you the same thing, my CRT is just more fluid, and i'm even running it at 'just' 85hz. I can predict my actions better if that makes any sense. Every time i get to play something at work or at a friend's house, especially when they have a god-awful cheap LG-paneled rebranded LCD... i can tell the difference. Just feels off.

We can go into talking about motion perception, phi effect, stroboscopic effect and refresh rates until the cows come home, but end of day, the CRT just 'feels' smoother. Attach to that anything you want, but there's a good reason i'm dreading the day my CRT will crap out and die. The Overdrive-teched IPS Ezio monitor to my right just seems like a horrible punishment to replace it with.

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