Question / Help OBS Frame-rate drop

[Frecky_D]

Hi, All.

So as of around 4 weeks ago (give or take) I updated my NVIDIA drivers as well as OBS, and ever since then I've been experiencing an issue whereby the frame-rate in OBS (and only OBS) drops to +-10fps and makes my stream look like a slideshow.
I hadn't changed any settings nor done anything differently, it just stopped working like it had in previous months and to date is still "broken".

I see A LOT of similar themed threads on here with little no answers... is there something I'm missing or that I've done wrong? How do I fix this?
I have found that this only happens on certain games. For e.g. it doesn't happen when streaming Dota2 or Ring Of Elysium, but does happen when streaming PUBG, Battlefield, AC Odyssey, COD and pretty much any other new title.

Hardware: 7700k (delidded running @ 4.8GHz) and 2 x GTX1080ti's.
Recent log: Click

ANY and ALL help would be greatly appreciated.
*edit*: Note: This drop in FPS occurs as soon as I open up the game, I don't have to be streaming or recording for it to happen.

 

[koala]

Your log contains this:

21:43:54.678: Output 'adv_stream': Number of lagged frames due to rendering lag/stalls: 358644 (51.6%)

This means, OBS was not able to render 51% of your frames on the GPU. This is a sign of severe GPU overload.

In the profiler section, this can be found:

21:44:10.299: ┃ ┃ ┗download_frame: min=0 ms, median=12.308 ms, max=181.356 ms, 99th percentile=92.88 ms

This means, half of the frames (median) took 12.308 ms or less to download from the GPU to the CPU. This value is much too high. It should be less than 1 ms. This also means half of the frames took longer than that. The transfer limit with 60 fps is 16.6 ms, so we found your bottleneck here. OBS was not able to transfer about half of your frames from the GPU to CPU in time, so they were lost.

The bottleneck is the pci-express speed of the video card OBS is running on.

You have 2 cards built in, so they should both run with x8 pci-e speed. Verify with gpu-z that this is really the case. It looks as if the card OBS is running on is running on less than that. One of your cards may be not be seated properly or in the wrong pci-e slot. If your mainboard has 3 wide pci-e slots, verify with your mainboard manual that you placed the 2 video cards in the proper slots.
Usually, it is not recommended to use such a setup. A single card yields more performance with secondary applications like OBS. One single card can run on x16 pci-e speed, and for transferring huge amounts of video data over the pci-e bus for applications like OBS, this is much better.

 

[Frecky_D]

Your log contains this:

This means, OBS was not able to render 51% of your frames on the GPU. This is a sign of severe GPU overload.

In the profiler section, this can be found:

This means, half of the frames (median) took 12.308 ms or less to download from the GPU to the CPU. This value is much too high. It should be less than 1 ms. This also means half of the frames took longer than that. The transfer limit with 60 fps is 16.6 ms, so we found your bottleneck here. OBS was not able to transfer about half of your frames from the GPU to CPU in time, so they were lost.

The bottleneck is the pci-express speed of the video card OBS is running on.

You have 2 cards built in, so they should both run with x8 pci-e speed. Verify with gpu-z that this is really the case. It looks as if the card OBS is running on is running on less than that. One of your cards may be not be seated properly or in the wrong pci-e slot. If your mainboard has 3 wide pci-e slots, verify with your mainboard manual that you placed the 2 video cards in the proper slots.
Usually, it is not recommended to use such a setup. A single card yields more performance with secondary applications like OBS. One single card can run on x16 pci-e speed, and for transferring huge amounts of video data over the pci-e bus for applications like OBS, this is much better.

Thank you so much for the reply. I will check that all this evening (10am here now) when I get home from work.

 

[Frecky_D]

So I checked everything last night and both cards are seated properly as wel as both in pci-e x16 slots.

I uninstalled MSI afterburner and that gained about 1fps, but I’m still at 98-99% GPU usage on card 1 and still bottle-necking which is restricts the FPS from going any higher in OBS.

 

[koala]

Don't just look if they are in x16-capable slots. Look into the mainboard manual and check if they are in the correct x16 slots. If there are more than 2 x16 slots, it is obligatory to put them into the correct 2 slots. And get gpu-z and verify the pci-e speed of each card to be sure they are really running at optimal speed.