Huge FPS impact when recording (replay buffer)

[aech]

I have a weird problem with OBS - it causes, like in title, huge FPS drop.

CS GO benchmarks for example:
Average framerate: 664.06 - no OBS
Average framerate: 576.39 - OBS, 240fps recording
Average framerate: 623.50 - OBS, 60fps recording.

In Battlefield V I lose like 50-70frames when using replay buffer.

Any ideas what can cause this?


My PC:
ryzen 5 5600x + PBO2 OC
rtx3070
32GB RAM 3200 cl16
recording to SSD

Logs - https://obsproject.com/logs/6CbCzGfTkvOdEPBL

 

[qhobbes]

1. The new Windows 10 Hardware-accelerated GPU scheduling ("HAGS") added with version 2004 is currently known to cause performance and capture issues with OBS, games and overlay tools. It's a new and experimental feature and we recommend disabling it via these instructions.
2. Change the Preset from Max Quality to Quality. Max Quality uses 2-pass encoding which uses GPU.

 

[aech]

1. The new Windows 10 Hardware-accelerated GPU scheduling ("HAGS") added with version 2004 is currently known to cause performance and capture issues with OBS, games and overlay tools. It's a new and experimental feature and we recommend disabling it via these instructions.
2. Change the Preset from Max Quality to Quality. Max Quality uses 2-pass encoding which uses GPU.

1. After disabling it my FPS are even worse
2. Actually there is no noticeable difference between those two options in my case
Also for some reason if I don't launch OBS as an administrator I have like 600fps on average in CS GO benchmark

 

[qhobbes]

OBS uses your GPU to render the scenes. If really need 600+ FPS when recording at 240 FPS, then you should get a second computer for that.

 

[aech]

OBS uses your GPU to render the scenes. If really need 600+ FPS when recording at 240 FPS, then you should get a second computer for that.

It uses my GPU to render? Yes, but actually not at all. The only part of my GPU that it's using when recording is "Video Encode", not even 60% of it.
No, I don't need 600fps when recording, but not having huge FPS impact would be nice. It happens no matter if I have 600 fps in game or not.
For example, in Apex Legends or new CoD I also have frames decrease, like 50 or so (from 250 to 200 in apex, something similar in CoD).

Also I can record in 60fps but FPS impact is still here. Not that big, but still.

 

[Tomasz Góral]

e.g. maximum performance of your system is 650 fps (create simply scenes), if you use 'Video Encode', you need some 'power' from '3D' too send copy from frames from framebuffer to 'Video Encode' memory in this scenarion probably you can use 200 fps in '3D' and send 60 fps 'Video Encode'.
More complicated scenes need more time and power to prepare. Yes Nvidia have separatly chipset for encoding but still ned some time and power from main GPU for management. A priority is set for '3D' not for encoding.

 

[aech]

e.g. maximum performance of your system is 650 fps (create simply scenes), if you use 'Video Encode', you need some 'power' from '3D' too send copy from frames from framebuffer to 'Video Encode' memory in this scenarion probably you can use 200 fps in '3D' and send 60 fps 'Video Encode'.
More complicated scenes need more time and power to prepare. Yes Nvidia have separatly chipset for encoding but still ned some time and power from main GPU for management. A priority is set for '3D' not for encoding.

OK, but then why my GPU usage, in CS GO for example, is not even 50% but there is still big fps drop?

I forgot to mention that, but this issue occurs only on my RTX card in OBS, when I had rx580 from AMD I didn't have such a problem, at least when recording in 60fps with AMD codec.

 

[Tomasz Góral]

Use GPU-Z to save log from sensors.

 

[aech]

Use GPU-Z to save log from sensors.