Re: G-Sync 101 w/Chart (WIP)
Posted: 23 May 2017, 10:14
I've sent an email to Chris (Battle(non)Sense) in case he's interested in this, and he might be doing a quick test this weekend.
Who you gonna call? The Blur Busters! For Everything Better Than 60Hz™
https://forums.blurbusters.com/
Yes, it works. But obviously you will get stutter.drmcninja wrote:Does V-Sync with -2 FPS limit work without G-Sync? Meaning, does it work without giving you a lot of input lag?
That's because with vsync, the game renders more frames that the display can output. This results in every available frame buffer being filled. When that happens, the game stops rendering new frames. By the time those frames make it to the screen, they are based on very old player input.Why does V-Sync suddenly stop giving input lag in such a situation?
This is needed to guard against fluctuating frame times. G-Sync can tear even if the apparent frame rate is within g-sync range. In reality, some frame limiters are not very accurate and produce frame times that are too high followed by frame times that are too low. CS:GO for example has this issue. Enabling vsync solves the issue.Third question: If the fps is limited to 2 below the refresh rate, then why do you need V-Sync with G-Sync to begin with? Wouldn't G-Sync alone just sit at that framerate/refresh (i.e, 142fps/Hz on an otherwise 144Hz monitor). I thought V-Sync only has an effect when there's tearing from going above the monitor's refresh rate?
RealNC already provided accurate answers, but to further answer you, the first three questions will be answered in detail in my upcoming article, input latency results included. The third question is already pretty much answered in my existing article here, though even it will be overhauled with further explanations and corrections when my third article is released:drmcninja wrote:Does V-Sync with -2 FPS limit work without G-Sync? Meaning, does it work without giving you a lot of input lag?
And if not, why does that work when G-Sync is turned on? Why does V-Sync suddenly stop giving input lag in such a situation?
Third question: If the fps is limited to 2 below the refresh rate, then why do you need V-Sync with G-Sync to begin with? Wouldn't G-Sync alone just sit at that framerate/refresh (i.e, 142fps/Hz on an otherwise 144Hz monitor). I thought V-Sync only has an effect when there's tearing from going above the monitor's refresh rate?
Somewhat different question: Why does Overwatch's internal setting 'Display-Based' under frame limit option use 10 above the refresh rate whereas you're using 2 below?
So if I'm reading you correctly, using RTSS means you can just use G-Sync and do not need to enable V-Sync at all? Then why doesn't everyone just do this rather than enabling V-Sync which might introduce extra input lag?This is needed to guard against fluctuating frame times. G-Sync can tear even if the apparent frame rate is within g-sync range. In reality, some frame limiters are not very accurate and produce frame times that are too high followed by frame times that are too low. CS:GO for example has this issue. Enabling vsync solves the issue.
This is not an issue with accurate frame limiters though. RTSS for example does not have this problem; vsync off works just as well.
Depending on how v-sync is capped, anywhere from 1/2 to 1 frame of accumulated delay in my testing (full results coming in the article) if you limit one or more full frames below the refresh rate, thus the recommendation to set the FPS only a few decimal points below the refresh rate.Thanks for the explanations guys!
So... what's the input lag like when using V-Sync, without G-Sync, while frame-capped below the refresh rate? I.e, 118fps cap, 120Hz refresh rate, V-Sync On?
Is it more or less than Fast-Sync? Because I'm wondering what's the point of 300fps, 120Hz refresh, Fast Sync On when I can just do 118fps, 120Hz refresh, V-Sync On...
Nope. G-SYNC + V-SYNC "Off" is basically Adaptive G-SYNC; it's will tear, just not all the time. the V-SYNC in "G-SYNC + V-SYNC" is simply a poor label for the toggle that allows frametime compensation with G-SYNC enabled. It ain't really v-sync, and it doesn't introduce extra input lag inside the G-SYNC range, but it ensures G-SYNC shows only one frame at a time.So if I'm reading you correctly, using RTSS means you can just use G-Sync and do not need to enable V-Sync at all? Then why doesn't everyone just do this rather than enabling V-Sync which might introduce extra input lag?
Correct, RTSS will only limit the framerate, it will do nothing to eliminate tearing, and must be used in conjunction with a syncing method.drmcninja wrote: And correct me if I'm wrong, RTSS alone can't help me if I don't have G-Sync, right? I'll need to use either V-Sync or Fast-Sync to get rid of tearing? Or can I set RTSS @ my refresh rate and hope for the best? There's no impact on input lag with RTSS either, right?