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Nvidia Low Latency mode and ULMB
Posted: 31 Aug 2019, 03:53
by knypol
I'm curious if with latest feature of Nvidia driver Low Latency Mode "Ultra" do I still need to substract 0.01 frame with vsync on to reduce input lag when using ULMB?
Does it matter if I use double or triple buffer vsync? I found out that triple is much more fluid in Apex. Or should i use Nvidia panel vsync for ulmb?
Re: Nvidia Low Latency mode and ULMB
Posted: 31 Aug 2019, 04:02
by Chief Blur Buster
The new NVIDIA Low Latency Mode may make the low-lag VSYNC HOWTO less needed -- latency tests are needed.
Triple has more lag. The problem is you're doing a stutter-vs-lag tradeoff.
If you want fluidity, you should use GSYNC/FreeSync instead. It's usually lower lag than low-lag VSYNC ON.
Re: Nvidia Low Latency mode and ULMB
Posted: 31 Aug 2019, 04:10
by knypol
hmm U sure that triple has more lag than double?
Re: Nvidia Low Latency mode and ULMB
Posted: 31 Aug 2019, 06:36
by jorimt
^ With framerates
below the refresh rate, typically, yes, it does; "triple" buffer (obviously) means three buffers, whereas "double" means two.
Triple buffer only has
less input lag than double buffer when the "triple" we're talking about is a Fast Sync variant (or the like), and only when the framerate is above (usually well above) the refresh rate.
For reference, as stated in G-SYNC 101:
https://www.blurbusters.com/gsync/gsync ... ettings/4/
As for “triple buffer” V-SYNC, while the subject won’t be delved into here due to the fact that G-SYNC is based on a double buffer, the name actually encompasses two entirely separate methods; the first should be considered “alt” triple buffer V-SYNC, and is the method featured in the majority of modern games. Unlike double buffer V-SYNC, it prevents the lock to half the refresh rate when the framerate falls below it, but in turn, adds 1 frame of delay over double buffer V-SYNC when the framerate exceeds the refresh rate; if double buffer adds 2-6 frames of delay, for instance, this method would add 3-7 frames.
“True” triple buffer V-SYNC, like “alt,” prevents the lock to half the refresh rate, but unlike “alt,” can actually reduce V-SYNC latency when the framerate exceeds the refresh rate. This “true” method is rarely used, and its availability, in part, can depend on the game engine’s API (OpenGL, DirectX, etc).
A form of this “true” method is implemented by the DWM (Desktop Window Manager) for borderless and windowed mode, and by Fast Sync, both of which will be explained in more detail further on.