Enabling V-Sync, NVIDIA G-Sync, and NVIDIA Reflex all together does not induce the frame limiter on Vulkan

[monstobusta]

ISSUE: when following the recommended video settings as shown by the CS2 steam support page (https://help.steampowered.com/en/faqs/view/418E-7A04-B0DA-9032#reflex), the intended effects only work on D3D11 and not Vulkan.

This can be shown when following the same methods on both D3D11 and Vulkan, namely turning on vsync and then reflex ingame while having gsync on in the NVidia control panel.
For reference, my monitor has a refresh rate of 165 hz, and has FreeSync Premium. Since I am using an NVidia GPU, this means that my monitor is merely G-Sync compatible, not actually G-Sync if that matters.

Here are the screenshots on DX11, with the telemetry showing the frametime and framerate in the top right corner. Alt text shows relevant info.

DX11 (intended/control behavior)




Vulkan (bad behavior); G-Sync's status does not show up in the settings menu.

 

[monstobusta]

Addendum:

From some more testing, I can conclude that if you turn on vsync, gsync, and reflex + boost on vulkan, you will still get the reduced input lag, lack of microstutters, lack of screen tearing, and variable refresh rate as one would expect. However, this only happens with a frame limiter manually set to reduce the framerate. Otherwise, normal vsync still kicks in.

 

[An Unoriginal Name]

If you need this to work in Vulkan, you can set the in-game frame rate to be the VRR cap for your monitor, set it via NVIDIA Control Panel's 'Max Frame Rate' setting, or force it via RTSS. I don't believe this function is supported in Vulkan so a frame rate limit isn't set correctly with the conditions met. Feel free to correct me if I'm wrong.