Odd stutters in captures I can't explain

zeta.stax

New Member
So I've tried to get rid of stutters in my streams and recordings, without success. I've cleaned up everything until I got a clean OBS log that doesn't show any warning or dropped frames etc. You can find it here https://obsproject.com/logs/2yE_pGcDqCIafsa1

Now there's some very odd behavior about the stutters though, they seem to be caused by absolutely nothing ? Let me explain. I made a 60 fps recording of a 60 fps game, using game capture (window capture and display capture both exhibit this behavior btw) and checked "capture cursor". While the game is playing I also move the mouse around for reference, and it turns out that when the stutters occur… only the game stutters in the capture, but not the cursor. At that point you're thinking "well then OBS isn't causing the stutters, your game is". Except it's perfectly smooth on my monitor and I have specifically disabled v-sync for this to make sure that it wasn't a trick of the refresh rate, so how is this even possible ? It does that with every single game, and it doesn't even matter how many fps I can get in game, like I'll still see those stutters if I'm hitting a constant 100 fps.

You can see the stutters here https://www.youtube.com/watch?v=_iR4OW4wKIU and if you go frame by frame you can clearly see that the mouse is still moving, so the capture isn't stuttering, but the game is, although it actually isn't lol. They're like phantom stutters. I don't know what else to do at this point, I've updated drivers, reinstalled the whole computer, changed every single component one by one, including multiple monitors and cables and what not. And I've been having those issues for over 2 years now. For a long time I just thought it was some sort of bug, but now that I've captured this behavior with the cursor, I don't know what to think anymore. I hope someone has an idea, thank you.
 

rockbottom

Active Member
Your log looks good but more can be done. Give these a try.

The monitor @ 144 isn't helping to reduce the stuttering. Run it & the game @ 60FPS while you are testing. After the stuttering is gone you can try the higher frame rates.

Update the capture device to 60FPS if possible & Sampling Rate to 48k

Scene "Dual" has two Game Captures, create another Scene for one of them.

Go into the Nvidia Control Panel, set Monitor Technology to Fixed Refresh (G-SYNC off) & V-sync back on, I have that set to Fast.

Encoding settings, Preset P6 is recommended & qres multipass can be enabled.

 

zeta.stax

New Member
Your log looks good but more can be done. Give these a try.
None of these change anything. Like I said I tried different monitors. As a matter of fact I event went back to a 1080p 60 Hz monitor that predates the invention of G-sync. It does the exact same thing.

Update the capture device to 60FPS if possible & Sampling Rate to 48k
The video I posted was not captured on the elgato, it's a game capture, not *the* game capture. Those settings cannot be changed by the way but it doesn't matter, got rid of the whole thing in OBS, same thing.

Scene "Dual" has two Game Captures, create another Scene for one of them.
OK this I don't understand. The log analyze also mentions that, but the scene doesn't have multiple captures, it's a single capture that is present twice with different transforms. But I removed the scene nonetheless, still the same.

Encoding settings, Preset P6 is recommended & qres multipass can be enabled.
This is happening on any encoding preset, be it nvenc or h.264, even at the lowest quality.
 

zeta.stax

New Member
No hold on. Actually using vsync fast seemed to do the trick when syncing to 59.97 Hz. Although OBS preview is still stuttering, the recordings are smooth. Thank you for putting me on the right track.
 

rockbottom

Active Member
Cool, should be able to get that Preview running smooth too. Since I don't know the config of your PC, verify that your GPU PCI-e slot is running @ x16 4.0. I tested my 3090 @ x8 4.0 & render times were over 6ms with lots of Preview stuttering. With it @ x16 4.0 render times are less than 1ms & the Preview is perfectly smooth.
 

zeta.stax

New Member
Well unfortunately the issue is still present, although it behaves differently now. Like I said OBS preview isn't running smoothly, I can still see a lot of stuttering. Sometimes those stutters are not in the recording, and sometimes they are. But now the drops are far more spread out but also much longer. It looks like the capture is not in sync and I'm getting 30 fps suddenly. Once again nothing reported in OBS log. Still, as I play there are no frame drops or any lag spikes visible on screen, although I'm in 60 Hz and not even in fullscreen, so I'm not convinced having vsync enabled in NVCP has actually any impact.

I've checked my BIOS, its configured in auto mode, and the PCI latency timer is set to 32.
 
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