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Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 18 Jan 2019, 18:30
by Chief Blur Buster
RealNC wrote:Higher CPU usage with RTSS is normal, and it doesn't have ill effects. The CPU usage is due to RTSS doing an idle loop for better frame timing accuracy. This generates a kind of "fake" CPU load. It doesn't result in high temperatures or anything. It just loops the CPU doing nothing, but this still registers as CPU load. Basically, RTSS loads the CPU with nothing. It just kills time. The game is blocked by the RTSS frame limiter anyway, so this doesn't take away CPU resources, as the game is prevented from doing anything anyway by the frame limiter.
It's normal.
Correct. The CPU is burning power (busylooping) to gain sub-millisecond framepacing accuracy.
Since you're capping framerate anyway (slowing the frame rate down for improved frame pacing), you're creating some unused processing room, which can be repurposed to improve framepacing even further.
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 18 Jan 2019, 18:31
by Chief Blur Buster
hejonar wrote:I am not using any form of sync, I was more interested in knowing would it affect input lag. Also, I've heard about frame skipping issue, so I guess that running 30 or 60fps at 75Hz would be worse than running 30/60fps at 60Hz?
There will be more stutters (on a non-VRR display) capping at non-integer divisors of refresh rate.
VRR displays like FreeSync/GSYNC makes that unnecessary, as all framerates can be perfectly smooth. (See
VRR demo)
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 19 Jan 2019, 08:04
by hejonar
Thanks for all those answers. I don't have VRR display but at least now I know what to get. I've decided to lock my monitor at 72Hz and use 36fps for this particular game.
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 28 Jan 2019, 23:10
by hejonar
So I have been browsing internet to check more possible options and found this video from 2017:
https://www.youtube.com/watch?v=mVNRNOc ... u.be&t=599
The author claims that enabling Game Mode/Game Bar in Windows 10 has reduced his input lag by 5ms. It was definitely different Game Mode by then(Microsoft keeps changing those "Fullscreen Optimizations" very often) but I do wonder is it true or not right now for Windows 1809. Perhaps it's case specific?
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 28 Jan 2019, 23:24
by RealNC
hejonar wrote:So I have been browsing internet to check more possible options and found this video from 2017:
https://www.youtube.com/watch?v=mVNRNOc ... u.be&t=599
The author claims that enabling Game Mode/Game Bar in Windows 10 has reduced his input lag by 5ms. It was definitely different Game Mode by then(Microsoft keeps changing those "Fullscreen Optimizations" very often) but I do wonder is it true or not right now for Windows 1809. Perhaps it's case specific?
I don't know. Could be. One thing though: game mode and fullscreen optimizations are unrelated. They're different things.
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 29 Jan 2019, 01:04
by hejonar
Indeed, all those three things "Game Mode", "Game Bar" and "Fullscreen Optimizations" are different things. Last one is pretty simple but I do wonder would disabling "Game Bar" while leaving "Game Mode" on like on that video work in 1809? AFAIK in 1709 you could not use "Game Mode" without "Game Bar" itself but now "Game Mode" is enabled by default for all games. It's really horrible how Microsoft changes are messing things up lately... very confusing.
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 29 Jan 2019, 10:33
by jorimt
hejonar wrote:So I have been browsing internet to check more possible options and found this video from 2017:
https://www.youtube.com/watch?v=mVNRNOc ... u.be&t=599
The author claims that enabling Game Mode/Game Bar in Windows 10 has reduced his input lag by 5ms. It was definitely different Game Mode by then(Microsoft keeps changing those "Fullscreen Optimizations" very often) but I do wonder is it true or not right now for Windows 1809. Perhaps it's case specific?
I posted about this video while writing G-SYNC 101:
viewtopic.php?f=5&t=3073&start=260#p26491
My (off-the-record) results (using virtually the same methodology as his) showed no input lag increase/decrease on my side, so I concluded it was likely a system specific difference.
hejonar wrote:Indeed, all those three things "Game Mode", "Game Bar" and "Fullscreen Optimizations" are different things. Last one is pretty simple but I do wonder would disabling "Game Bar" while leaving "Game Mode" on like on that video work in 1809? AFAIK in 1709 you could not use "Game Mode" without "Game Bar" itself but now "Game Mode" is enabled by default for all games. It's really horrible how Microsoft changes are messing things up lately... very confusing.
Yeah, they keep changing implementation around, and it's hard to tell what combination of which does what exactly anymore.
As of now (1809), I leave Game bar off, Game Mode on, and disable/enable fullscreen optimizations selectively (per exe), since G-SYNC seems to rely on FSO enabled in some older games to function in exclusive fullscreen mode now (not something you have to worry about with your current setup though, obviously).
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 29 Jan 2019, 10:41
by RealNC
jorimt wrote:As of now (1809), I leave Game bar off, Game Mode on, and disable/enable fullscreen optimizations selectively (per exe), since G-SYNC seems to rely on FSO enabled in some older games to function in exclusive fullscreen mode now
Disabling FSO will result in Windows running games in a compatibility shim, as with the other compatibility settings. This can indeed mess with things. FSO is now the "native" mode to run games, disabling it activates the legacy shims, meaning redirections and hooks all over the place.
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 29 Jan 2019, 10:55
by jorimt
Yup, I added an entry about FSO in my recent G-SYNC 101 FAQ section.
Basically (casual, observance-based testing here), it's seems like it's no longer safe to globally disable FSO when using G-SYNC with exclusive fullscreen due to what you mentioned; some games won't allow G-SYNC functionality with it off currently.
Personally, I've been testing some of my most played games with FSO off/on + G-SYNC + exclusive fullscreen (mainly Destiny 2, which has some obnoxious server-side frametime issues in public instances that no user-side settings can do anything about), and I've had a hard time noticing any difference between FSO on/off (no apparent input lag increase or worse overall frametime performance with it on).
So, currently, I'm thinking that disabling FSO for G-SYNC purposes, at least with the latest Windows 10 version, is no longer necessary in the majority of situations.
Obviously, Microsoft could always change the implementation (and, as per usual, never let us know how exactly), and FSO enabled still seems to cause some quirky behavior with DPI/DSR in borderless/windowed in some circumstances (though I personally don't use DPI scaling, DSR, or borderless/windows much either).
Re: Lowest input lag on normal 60Hz monitor with fps limiter
Posted: 30 Jan 2019, 07:06
by hejonar
RealNC wrote:jorimt wrote:As of now (1809), I leave Game bar off, Game Mode on, and disable/enable fullscreen optimizations selectively (per exe), since G-SYNC seems to rely on FSO enabled in some older games to function in exclusive fullscreen mode now
Disabling FSO will result in Windows running games in a compatibility shim, as with the other compatibility settings. This can indeed mess with things. FSO is now the "native" mode to run games, disabling it activates the legacy shims, meaning redirections and hooks all over the place.
I see. Would those "compatibility enhancements" affect mouse/keyboard input delay?