Frame Timing & Fixing Game Stuttering With Display Timing Extensions

[phoronix]

Phoronix: Frame Timing & Fixing Game Stuttering With Display Timing Extensions

Back during GDC 2018, Alen Ladavac serving as the CTO of Croteam presented on their research and testing into frame timing for helping uncover why some games are stuttering even when being rendered at high frame-rates. The short story is the issue can be addressed by just not measuring the time for rendering each frame in a game but to measure the time needed to actually present that frame on a display output. For that there is VK_GOOGLE_display_timing for Vulkan and other similar extensions...

http://www.phoronix.com/scan.php?page=news_item&px=Frame-Timing-Game-Stuttering

[johanb]

Very interesting article.

This is what I expected v-sync to achieve, but apparently v-sync is more basic than that and is not aware of when the frame is actually displayed.

The only annoying issues I've had with stuttering is when playing Skyrim through wine even though I run at ~80fps, I hope that will be fixed some day.

[theriddick]

I've always known about this issue, quite common in OpenGL games such as WarThunder for example.
High frame rates but a rather choppy experience and not at all smooth, I believe Tomb Raider had this issue also. DirectX games had a tendency to NOT suffer from these sort of problems, as was apparent when using DXVK to do comparisons against native linux game releases.

[R41N3R]

I'm very happy that Croteam addressed this. I've seen it my self often enough, but I just thought that must have been just a driver issue.

I see this kind of stuttering with a AMDGPU when playing videos via Firefox on XWayland on a 4k screen. I guess that XWayland is maybe quite bad for stutterfree playback at the moment.

[aufkrawall]

When I see stuttering, it's usually the game itself. And usually it's shader compile stutter as seen in Fusion engine with OGL & Vulkan...

[GunpowaderGuy]

Some os have been discussing turning off accurate timing to make spectre impossible to exploit , would that prevent the use of this extension ?

[TheOne]

I wonder if the same technique could be implemented on the Xserver compositors for tear free desktop...

[clintar]

Frankly, I'm just completely disappointed that this hasn't been figured out before. Developers have worked on this kind of thing forever. It's not like rendering is in its infancy at this point.

[TheOne]

Some things take a lot of time to figure out mostly because as developers they are more focused on making stuff work... And since hardware is always increasing in power an issue like this was bypassed by many years. I for example never noticed any issues on the quake3 engine running at 125fps, but with the more demanding games putting into shame the most powerful GPU hardware, then something got to be wrong somewhere...

[HenryM]

I recently discovered a weird bug in the CS:GO Panorama UI; as long as any in-game timer is visible, a big frame-drop will occur on every update of the displayed time. disabling the HUD stops the spiking. this issue might only happen with the Panorama UI on Linux. old UI seems fine, windows is fine. I wonder if it is related to this: https://www.phoronix.com/scan.php?pa...ce-Fix-Clutter