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V-sync

Author Topic: V-sync  (Read 2248 times)

Online Joe

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V-sync
« on: October 07, 2016, 01:44:31 PM »
Anyone running with V-sync on?

Since moving to triples I had to turn the settings down a tad to maintain a near constant 60fps but I'm getting a lot more tearing than I used to. I just had a quick go with V-sync on and it was super smooth, and not really any noticeable input lag. Even did a PB.

Unsure whether to turn some settings up again to avoid going over 60fps or leave V-sync on. The input lag you'd get would be different for every game, but didn't seem any different to me with AC.

Rolz

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Re: V-sync
« Reply #1 on: October 07, 2016, 01:47:08 PM »
Even did a PB.

Probably due to the fact u have a new rig :P

I haven't had v-sync on for ages, but will test and revert back


Online Wally

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Re: V-sync
« Reply #2 on: October 07, 2016, 01:51:22 PM »
I  have vsync on but only because it's the only way I can get a tear-free experience. Everything else I've tried always ends up in some tearing.
“You can please some of the people all of the time, you can please all of the people some of the time, but you can’t please all of the people all of the time”

Online Joe

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Re: V-sync
« Reply #3 on: October 07, 2016, 01:54:15 PM »
I  have vsync on but only because it's the only way I can get a tear-free experience. Everything else I've tried always ends up in some tearing.

Yeah I tried different frame limits and some were better than others, but v-sync just looks nicer and didn't feel any lag myself. Will keep it on for a while, at least until I can afford some monitors with a higher refresh rate.

Online Bacchulum

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Re: V-sync
« Reply #4 on: October 07, 2016, 02:05:39 PM »
What does V-sync do?
Should I have it on?
I have everything on and on max, because I can, but should I?
I'm so confused...

Online Joe

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Re: V-sync
« Reply #5 on: October 07, 2016, 02:32:12 PM »
It syncs the number of frames output by the GPU to what your monitor can handle. Most only have 60hz monitors, so they can't handle any more than 60fps before you start to see screen tearing. V-sync stops the tearing, but does introduce some input lag.

Pretty good article here on it:
http://www.displaylag.com/reduce-input-lag-in-pc-games-the-definitive-guide/

Online Bacchulum

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Re: V-sync
« Reply #6 on: October 07, 2016, 03:22:12 PM »
So, because I have my fps capped at 60, I don't need it? :)

EDIT
What's 'tearing'? ???

Online Joe

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Re: V-sync
« Reply #7 on: October 07, 2016, 03:35:57 PM »
It's basically where you are missing frames as your monitor can't keep up, a bit like this:
https://camo.githubusercontent.com/eca45d7d1e44a2f78541c27fe49f5e28fe66be0e/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f333738393232362f3439323436372f34323630643034612d626162322d313165322d383731662d3338316536343163336538332e706e67

It could be that fully maxed out your not getting over 60fps so you won't notice it, as even with frame limiting I had it. When I first went to 3 monitors fully maxed I was getting framerate drops into the 40s so I turned a few settings down.

Online Gratulin

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Re: V-sync
« Reply #8 on: October 07, 2016, 04:06:24 PM »
So, because I have my fps capped at 60, I don't need it? :)

EDIT
What's 'tearing'? ???
If you don't know what it is you haven't got it ;)

Online Bacchulum

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Re: V-sync
« Reply #9 on: October 07, 2016, 04:42:39 PM »
So, because I have my fps capped at 60, I don't need it? :)

EDIT
What's 'tearing'? ???
If you don't know what it is you haven't got it ;)
Thought so.
After seeing Joe's pic, I ain't got that. 8)

And I was getting around 100fps before I capped it (can't remember why I capped it). :-\

Online Joe

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Re: V-sync
« Reply #10 on: October 07, 2016, 04:53:32 PM »
Maybe have have a high refresh monitor in which case it can handle more frames

Online Gratulin

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Re: V-sync
« Reply #11 on: October 07, 2016, 04:54:01 PM »
I was same as Wally. Needed vsync otherwise got tearing and micro freezes. That was before latest round of software upgrades from AMD and AC. Not sure which one fixed it but performance is up by about 20% and no need for vsync anymore. So depends on GPU, CPU, monitors, DVI (or other), software versions etc etc.

Online Joe

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Re: V-sync
« Reply #12 on: October 07, 2016, 05:11:42 PM »
The monitors i have were cheap gumtree ones to get me by until i can afford some better ones. I may get some 75hz ones then i wouldnt need to worry.

Online grat

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Re: V-sync
« Reply #13 on: October 07, 2016, 06:07:32 PM »
I run v-sync AND limit at 60fps, otherwise I get either tearing or small random stuttering/freezes.

This thread http://www.assettocorsa.net/forum/index.php?threads/maximum_frame_latency-does-it-still-work.37075/ has some interesting numbers on input lag and how a parameter in the .ini files apparently can change that with or without vsync on.

Offline marty

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Re: V-sync
« Reply #14 on: October 07, 2016, 06:29:13 PM »
V-sync is a simple option that holds frames back to then only display full frames and sync to the monitors refresh rate. This means it renders a frame then has another 1 or 2 frames delay before it displays the image. V-sync off will just render the next availiable frame and as the monitor draws an image line by line top to bottom rather then a full screen at once. With v-sync off its possible one frame is being drawn and before this is finished the next frame will be displayed on the lower half of the screen. This means the top and bottom of the image may not match up and its called screen tearing. If your outputting very inconsistant frame rates then it will cause stutters as it renders frames not equally spaced apart.

I did some testing not long ago to see if fps made a difference and also if v-sync on or off made a significant difference. I normally just run capped at 63 on my 60hz screen with v-sync off. I tried turning some settings down and got AC to over 900fps lol and then went back to my capped refresh and there was no effect on driving or laptimes. Higher frame rates looked considerably smoother and better motion but it had no effect on my inputs.

I then tried v-sync and the lag clearly was effecting me any time the car would slide, if you drive only to a predictable stable type of car the added lag you can deal with by simply driving by memory. Its pretty much impossible to drive reactively as v-sync adds an extra 1 to 2 frames delay beyond the delay already in your monitor and system. This simply means anything not predictable will be much harder to deal with and quite often by the time you see something its too late to react to it.

V-sync on clearly gives a smoother image, but you can find a fps to cap at that minimizes tearing. Id rather see some tearing then see my car spinning off track unable to save it simply to have a slightly cleaner image.

It will also greatly depend on the monitor your using, worst case scenario is pretty much any tv as they add lots of signal processing and can add 2 to 4 extra frames of delay to displaying the image. V-sync will add another 1 or 2 frames so you can be seeing things up to 6 frames or 1/10 of a second after they have been rendered. Turning on or off v-sync on a very laggy display wont even be that noticeable as its not that big a factor in the overall lag.

There are screens using nvidia v-sync or free sync which eliminate tearing without need for v-sync and its the best option. If you can get the game to run at more then 2x your refresh rate then it will normally produce a smooth stutter free image and minimal tearing. I find if I cant get the game to consistently run at above 120fps then its better to cap close to 60 as 60-110 seems very stuttery to me and looks more like 30fps then 60.