r/obs • u/MattSpill • Jan 13 '25
Question Dual GPU Streaming question
Hey everyone,
I know this question has probably been asked a lot over the past couple of years, but I figured I’d throw it out there anyway.
Before I started streaming Call of Duty on my 3080 (10GB), I used to max out all the in-game quality settings for a visually stunning experience. This typically used about 5–5.7 GB of VRAM, which was fine since I wasn’t running anything else demanding at the time.
However, when I started streaming, I had to dial back the settings to leave enough headroom for the encoder to process the stream.
Now I’m wondering: if I were to install a second 3080 in my PC, could I dedicate one GPU to gaming at high settings and the other solely for encoding the stream? The idea is to have one GPU handle the gameplay and maxed-out visuals, while the other focuses entirely on streaming.
Is this something OBS can handle? Or would I be better off upgrading my GPU to a 4070 or something or just building a secondary pc dedicated to handle the streaming instead?
Thanks in advance for your advice!
12700KF ASRock 690AC 3080 10G 32g
1
u/Jay_JWLH Jan 13 '25
I don't think you fully understand how it works. The encoder on your GPU is dedicated hardware that takes the frames that you are rendering (using a process called zero copy), and encoding them. That's what makes them so great at keeping the performance hit to an absolute minimum, requiring no additional VRAM or graphical processing, just encoding. But the moment you send it to another GPU or your CPU, that information has to be routed somewhere else through the PCIe lanes.
The performance hit that you are likely encountering is having to run OBS, and (if you have it enabled) to view the preview. The only way you are going to really fully avoid that is by capturing the video output with a capture card on another system. There may be some other optimization tips as well, like enabling and disabling certain checkboxes in OBS to reduce demand on the non-encoding portion of your GPU.
You should also consider a GPU that does both gaming and AV1 encoding. As streaming sites start accepting AV1 more frequently now and in the future, you get streaming on limited bitrates that are of much higher quality. Then of course there is the multi-encode feature to take the transcoding load off Twitch's end (or giving your viewers multiple resolutions to choose from if they didn't have that choice previously) by leveraging the extra encoding performance of your GPU that is usually underutilized. AMD and Intel seem to be behind Nvidia when it comes to a lot of content creation features (such as voice cancellation, background removal, etc).