Question / Help Only opening OBS make games drop FPS

[n3v3rm1nd]

Title.
So i lose around 10fps i think after i started to stream. I don't have any fancy sources or scenes. Sources in total of 4. My gaming Scene has 10 sources for some overlay pictures and the webcam.

Is this normal behavior or is there anyway i can reduce the GPU load from OBS? Since losing around 10fps is a pretty big deal.

Here is a log after i made a short recording with my stream settings in record https://gist.github.com/4d3d3ca72f631f8f968f53b3595ec0ba

 

[SachaPvP]

exact same for me. I don't even have to start recording to loose the FPS... I just loose it once OBS is open by itself... Are you recording Minecraft? what game?

 

[n3v3rm1nd]

It doesn't matter what game. This one was GTA5 for example. OBS is open i lose frames. I'll have to go back to 30fps streaming for now. There are really now alternatives to OBS, Xsplit maybe but that seems to be an even bigger performance hog, but i really don't know.

 

[BK-Morpheus]

OBS uses the GPU to compose your scene, scale it down, apply filter and render the frame, so it can be encoded.
If your OBS video setting is more demanding (high resolution, high framerate), the amount of GPU power that is needed for rendering will increase.
That's normal and neither an additional GPU, nor disabling preview will change that.

 

[n3v3rm1nd]

OBS uses the GPU to compose your scene, scale it down, apply filter and render the frame, so it can be encoded.
If your OBS video setting is more demanding (high resolution, high framerate), the amount of GPU power that is needed for rendering will increase.
That's normal and neither an additional GPU, nor disabling preview will change that.

But why do i have so suffer from a whopping 10fps loss? Isn't this a little bit too much??

 

[BK-Morpheus]

It depends on your OBS video settings and on your ingame fps.
If your game is running at 100fps or more, a performance hit of -10fps is pretty normal.
If your game is running at 50fps, a performance hit of -10fps is on the heavy site and I would consider more than normal.

 

[n3v3rm1nd]

It depends on your OBS video settings and on your ingame fps.
If your game is running at 100fps or more, a performance hit of -10fps is pretty normal.
If your game is running at 50fps, a performance hit of -10fps is on the heavy site and I would consider more than normal.

I lock all games on 60fps and every game i play easily achieves that, just for testing purposes i unlock them to see what kind of a hit i take.

Seems like nothing can be done about that other than to upgrade to a better GPU or hope for a better optimization on that end. OBS is the only software right now that can do all i want. Tried Xsplit and it's horrible. I don't even know how they are making money off of it?!

If only Nvidia could open up their recording method via share so we could all have a nice performance boost that would be nice...But someone can dream right? xD

 

[BK-Morpheus]

True...would be cool, if OBS could access the video memory, the ways Nvidia is doing it with their NVENC encoder chip, but I don't think it's possible (if the encoder chip has direct access, there is no extra load on the PCIe bandwidth and the only transfer is from the encoded stream to the computer, which has already way less bandwidth-load compared to direct video hooking).

 

[n3v3rm1nd]

True...would be cool, if OBS could access the video memory, the ways Nvidia is doing it with their NVENC encoder chip, but I don't think it's possible (if the encoder chip has direct access, there is no extra load on the PCIe bandwidth and the only transfer is from the encoded stream to the computer, which has already way less bandwidth-load compared to direct video hooking).

Yepp, but won't happen since it then directly competes with it, but optimizations can always happen :)

 

[BK-Morpheus]

I found some very interesting information on the reasons behind the low performance impact of NVENC (besides the encoding process itself):
https://forums.guru3d.com/threads/m...beta-16-2013-10-25.382760/page-4#post-4687310

That posting is pretty old, but still true. The frame buffer access of Nvidias own capture solution is the key.
Maybe that's the reason, why this access is locked since ~2014.
"In new drivers NVIFR and NVFBC are now completely locked by NVIDIA for their internal tools only. Some green(dy) vendor want to artificially limit performance difference between Shadowplay and traditional video capture tools."
source: https://forums.guru3d.com/threads/gpu-encoding-uses-cpu.395727/#post-4983364

 

[n3v3rm1nd]

Yeah like i said i only lose like 4-5fps when starting to stream. Thats not bad. Share is still much better though like 1fps or nothing at all, but because of the above mentioned methods.

if i recall correctly i did not have such an issue in the past where i lose 10fps. Maybe something happend, more compatibility etc. then thats what could cost frames. Like I see OBS can capture a fuckton of things and you can add so many stuff I think they need to do what they do under the hood.

What if you offload some of the stuff to the CPU? Probably be worse i think. Me with an i7 not so but my son with his i3 could have some issues then.

 

[n3v3rm1nd]

There just came an Update out with this changelog:
Optimized the preview pane and reduced GPU usage by 2-8% depending on how many sources were in the preview.

Will test this week and hope it will be a little bit better :D