Question / Help SLI Performance issue

[Simon Olsen]

Hi all!

I'm relatively new to streaming and I am having this issue I hope someone can help me with.

I usually stream CS:GO, but after getting my second graphics card and setting it up in SLI, I am having performance issues (which is kind of strange, because my computer should be able to stream CS:GO without any issues).

My system:
CPU: i7 4790k
GPU: 2x Geforce GTX 980
Memory: Corsair Dominator Platinum 16GB
Motherboard: ASUS Z97-A ATX
Storage: Samsung 850 EVO 500GB
OS: Windows 10 64bit

My connection:
150 Mbps down
7.5 Mbps up

If I play CS:GO without streaming, my FPS hovers around 400-600. While streaming, the FPS drops to 100-200 (and is mostly sub 150). It also feels like I am having micro stuttering (It is hard to explain, but I get intervals where everything just feels a little delayed).

Before I got my 2nd GTX 980, I could stream with an average of 200-300 fps (sometimes sub 200, but that was fine). How can setting two cards in SLI change performance like this with OBS? Can anyone recommend what settings I should use for my stream?

 

[Osiris]

OBS can only get the frames from one gpu, and since that one gpu only renders half of the frames, your fps will drop.
OBS multiplatform has multi-adapter compatibility, but that means all frames will be copied to memory, which is slower then grabbing them directly from the GPU. Not sure if that is slower then the performance hit by SLI.

 

[Simon Olsen]

OBS can only get the frames from one gpu, and since that one gpu only renders half of the frames, your fps will drop.
OBS multiplatform has multi-adapter compatibility, but that means all frames will be copied to memory, which is slower then grabbing them directly from the GPU. Not sure if that is slower then the performance hit by SLI.

Thank you for a fast reply. So I am better off just to disable SLI whenever I stream? Also, I could see why the stream would be choppy from only getting half the frames, but why would my game be affected by this limitation?

 

[defterOG]

Thank you for a fast reply. So I am better off just to disable SLI whenever I stream? Also, I could see why the stream would be choppy from only getting half the frames, but why would my game be affected by this limitation?

yes, disabling SLI would be the best option when streaming. however, if you really want to be able to use SLI while streaming, you could also use DxTory and then use OBS's video software capture (or something like that). but, using that method will also tax your CPU more compared to OBS's game capture.

i used to have a GTX 670 SLI setup and using DxTory with OBS gave me best results. just remember your CPU is already using more resources to begin with as it's working with 2 GPUs instead of 1, and trying to stream on top of that as well can get extremely demanding.