Question / Help stream and record simultaneously (with GPU instead of CPU)

[Nekonomicon]

Hello everyone,

I downloaded OBS to stream computer games on Twitch-TV, but I also want to capture everything from source to original quality.


My PC is not a high-end gaming PC but rather weak.
If someone needs information about my hardware or software I would like to provide it.

Basically, my question is: whether I can use the multiple graphics cards despite low CPU power (3.70 GHz) and 8GB DDR3 liquid stream and record at the same time.

I've got some older but far from scrap ready graphics cards and I can use up to 3 on my motherboard.
All graphics cards have at least 4GB of DRAM and almost all Radeon chips.

I would like to know if I can use graphics cards as a resource source for OBS.

Upgrading my PC is not an option, because as a student who is not supported by his family, I pay all living expenses, school supplies, rent and everything else myself. Although I work alongside the school as a temporary help, there is no money left to invest.

I am grateful for any answer, tip or even alternative solution.

Yours sincerely,
Neko

PS: I'm sorry for my bad english ^^

 

[koala]

Generally, OBS works best with only 1 graphics card plugged in the PC. While it sounds good if you were able to distribute GPU load between multiple cards, it is actually not possible. The issue is that transferring data from one GPU memory to the other's GPU memory is using up more resources than any processing by multiple GPUs would save.
So choose the best GPU you have for your project and go with that.
If you have a CPU with an iGPU (integrated GPU), this is a bit different. The iGPU of Intel Core-I processors provides the Quicksync hardware encoder, which encodes your video with practically no CPU load, so this is desirable if you don't have CPU cycles to spend.
Nvidia graphics cards from the GTX 600 and upwards have the Nvenc hardware encoder, which is quite better than the Quicksync hardware encoder, and it is usable from OBS with lesser system resources, so if you have a Nvidia GTX 600 or above, this would be a good graphics card for recording or streaming.
The AMD cards also have a hardware encoder, but it provides the least quality in comparison to nvenc and Quicksync. It also uses shared GPU resources, so if the game you capture fully uses the GPU, the AMD hardware encoder stalls and isn't able to produce stable data. If you only have AMD cards, but you have an Intel CPU, you might look into the BIOS of your computer if you are able to activate the iGPU to enable Quicksync for OBS.

So it boils down to this:

1. if you have an Nvidia GPU, use this GPU and use the nvenc hardware encoder with OBS
2. if you have an AMD GPU, and you have an Intel CPU, try to activate iGPU in the Bios and use the Quicksync encoder with OBS
3. if you have an AMD GPU and no Intel iGPU, use the AMD hardware encoder. You will probably have to tune down your resolution, fps and game settings to some extend.
4. if you aren't able to activate any hardware encoder, use software x264. Since this uses much CPU resources, you will probably have to tune down your resolution, fps and game settings even more, and also the output settings of OBS.