Using Multiple GPUs for Streaming

[RoyalWulfff]

Hello, specs and settings of current setup posted below. I am streaming (Twitch) using a 1 PC setup and it can sometimes be overwhelmed, as we would expect. The problems I have seen are the stream going down (believe to have resolved this with OBS prioritization), hitching in game, and poor FPS. My current GPU is limited in its capability and I am curious if the purchase of a second GPU could help the situation. Given my current limitations I am encoding on the CPU only (I think, please correct me if I am wrong).

The plan I am thinking of is to purchase a 30/40 mid series card. This would drive all outputs to my 3 monitors. I would set OBS to encode through the existing RTX4000. I dug a little in the forums and couldn't find much regarding something like this, my apologies if I missed something obvious. My concerns would be that the traffic still has to go from the new card to the CPU and back to the RTX4000 and that may be a bottleneck and negate any performance gains. Does anyone have an idea if this setup would be efficient?

PC Specs:
CPU - AMD Threadripper 3960X (24 cores/48 threads)
GPU - Nvidia Quadro RTX 4000 (Die is 2060/2070 based if im not mistaken)
RAM - 128 Gb @ 3200 MHz
Storage - Samsung NVME (OS/OBS), Samsung SSD (Games/supporting applications)
Motherboard - MSI Creator TRX40

Current OBS Settings for Output:
Video Encoder - x264
Rate Control - CBR
Bitrate - 6000 kbps
Keyframe - 2s
CPU Usage Preset - Slow
Profile - None
Tune - None
Resolution - 1920x1080 @ 60 fps

Let me know if any additional information is needed.

I do record to a hard drive (7200 RPM) not sure if this could/would have any affect.

 

[phasstphood`]

Dual stream a second pc and elgato capture video card to stream if you can afford it or adjust your in game setting if any problems lag and frame rate dips ..it depends on the game and your internet speed .. recording depends the format settings and besides your gear looks op you shouldn't have any problems .. just test your settings its not gonna be perfect every game .

 

[FerretBomb]

Is there a reason you're not using NVENC as the encoder? Set up correctly, NVENC has zero impact on in-game performance, as it is a separate part of the GPU die. NVENC on the 20-series through the 40-series is virtually identical, other than the 40-series' ability to encode in AV1.

2 GPU systems cause issues with streaming; plenty of people have had the idea, and it simply isn't worth the headaches. Even multi-GPU SLI setups are encouraged to move to single-card if possible. Since you're using CPU encoding (x264) it really wouldn't help anyway... most likely the performance issues you're seeing are the CPU being overrun and choking out.

Swap to NVENC, if nothing else to test.

 

[RoyalWulfff]

Dual stream a second pc and elgato capture video card to stream if you can afford it or adjust your in game setting if any problems lag and frame rate dips ..it depends on the game and your internet speed .. recording depends the format settings and besides your gear looks op you shouldn't have any problems .. just test your settings its not gonna be perfect every game .

Is there a reason you're not using NVENC as the encoder? Set up correctly, NVENC has zero impact on in-game performance, as it is a separate part of the GPU die. NVENC on the 20-series through the 40-series is virtually identical, other than the 40-series' ability to encode in AV1.

2 GPU systems cause issues with streaming; plenty of people have had the idea, and it simply isn't worth the headaches. Even multi-GPU SLI setups are encouraged to move to single-card if possible. Since you're using CPU encoding (x264) it really wouldn't help anyway... most likely the performance issues you're seeing are the CPU being overrun and choking out.

Swap to NVENC, if nothing else to test.

Dual PC would be the best, but with the cores I have I was hoping to get around it.

I was not using the NVENC because if I had it on the stream would crash during a specific map on Escape from Tarkov (main game I stream). The only way I found to not have the crashing problem was to switch to x264. CPU still wouldn't sit at 100% usage and rested between 60-70C (system is on a custom loop).

I ended up going for a 3080, to either replace or try the 2 CPU system. It worked without too many issues and has been incredibly stable for frames and bitrate during streaming.