Hidden settings in Nvidia Inspector that reduce lag
Posted: 20 Jun 2018, 15:59
Hi all,
I tried some (hidden) settings in Nvidia Inspector that appear to reduce input lag in the scenarios where you either let the frame rate hit and exceed the GSYNC limit (100 Hz in my case), or you use the Nvidia driver frame rate limiter accessible through Nvidia Inspector.
The settings are
"max_pending_command_buffers", which I have never seen mentioned before here. Default = no limit.
"Maximum frames allowed", which I have seen mentioned once before here, by RealNC. Default = 2.
"Maximum pre-rendered frames", well known setting, even available in Nvidia control panel. Default = app controlled.
With all three of these settings set to 1, input lag *seems* reduced from the defaults in cases I hit 100 fps and am capped by the GSYNC ceiling. Also when I limit frame rate to let's say 60 by using the driver frame rate limiter.
Edit:
the settings "Maximum frames allowed" and "Maximum pre-rendered frames" actually are the same thing, it seems. Nvidia Inspector just allows them to be set separately for some reason, however if you set "Maximum pre-rendered frames" in the Nvidia Control Panel, both settings are updated. The new setting that I believe improves input lag is then just "max_pending_command_buffers".
I'm lacking the hardware to test this for real. Except that I'm quite good at "feeling" the lag induced by limiting to 60 at defaults and using the TrackIR headset. Since TrackIR captures any head motion, any lag can be noticed rather easily. With the settings mentioned above all set to 1, lag feels almost absent, very similar to capping within game even.
[[Intermezzo: capping to 60 Hz, or an integer divisor of 120, is important for using TrackIR since its update frequency is 120 Hz, and smooth motion is impossible otherwise.]].
At this point I'm unable to provide more evidence. Perhaps someone with ready access to a high-speed camera and some interest in these settings could run a small test?
Cheers,
Vleeswolf
I tried some (hidden) settings in Nvidia Inspector that appear to reduce input lag in the scenarios where you either let the frame rate hit and exceed the GSYNC limit (100 Hz in my case), or you use the Nvidia driver frame rate limiter accessible through Nvidia Inspector.
The settings are
"max_pending_command_buffers", which I have never seen mentioned before here. Default = no limit.
"Maximum frames allowed", which I have seen mentioned once before here, by RealNC. Default = 2.
"Maximum pre-rendered frames", well known setting, even available in Nvidia control panel. Default = app controlled.
With all three of these settings set to 1, input lag *seems* reduced from the defaults in cases I hit 100 fps and am capped by the GSYNC ceiling. Also when I limit frame rate to let's say 60 by using the driver frame rate limiter.
Edit:
the settings "Maximum frames allowed" and "Maximum pre-rendered frames" actually are the same thing, it seems. Nvidia Inspector just allows them to be set separately for some reason, however if you set "Maximum pre-rendered frames" in the Nvidia Control Panel, both settings are updated. The new setting that I believe improves input lag is then just "max_pending_command_buffers".
I'm lacking the hardware to test this for real. Except that I'm quite good at "feeling" the lag induced by limiting to 60 at defaults and using the TrackIR headset. Since TrackIR captures any head motion, any lag can be noticed rather easily. With the settings mentioned above all set to 1, lag feels almost absent, very similar to capping within game even.
[[Intermezzo: capping to 60 Hz, or an integer divisor of 120, is important for using TrackIR since its update frequency is 120 Hz, and smooth motion is impossible otherwise.]].
At this point I'm unable to provide more evidence. Perhaps someone with ready access to a high-speed camera and some interest in these settings could run a small test?
Cheers,
Vleeswolf