I have a quadro 4000 and a Titan in my machine, but UE4 seems to be using the Quadro 4000. Is there any way I can tell UE4 to use a specific card / slot? I can’t physically move the cards around because of the configuration of the case.
Any information is greatly appreciated!
Normally you can change that in your nvidia control pannel -> the nvidia logo in the systray 
Just a short hint -> go to your power settings and change them to “high performance” This will also increase your fps rate
Hi
Can you please provide in more ditales how to choose thr specific card. I have 1080ti and 3090. UE4 uses only 1080ti. I dind’t find any setings in my nvidia control pannel to change the GPU
Appreciated for help
Is there a reason you have two different cards in your system? I would remove the 1080Ti and sell it
Actually i have two 3090 and one 1080ti.
I use 3090s for render purpose and to make the cooling of this cards more efficient i put them in a separate container and connected to my computer with pci extension cluster. Here is a devise that i use https://www.amfeltec/multi-gpu-cluster/
1080ti i use only to connect 3 monitors together. If i sell 1080 ti my render rig will not be efficient enough.
I also want to use 3090 for UE4. I found out how to choos the GPU in my nvidia control pannel but now i faced with another problem. UE4 crashes after i starting my file. But if i back my 1080ti GPU, the file works fine again.
What can be the reason of that crashed?
If you have SLI enabled then disable it, if you are using the Nvidia Control panel and you have it set to use the 3090 for UE4 then that might not work and you might need to set it to use the 3090 globally as the default rather than setting it for the program by itself
Someone found out how to select GPU ??
Refer to this post: Explicitly choosing which GPU to use - Community / Community & Industry Discussion - Epic Developer Community Forums (unrealengine.com).
In short, use command line argument: -graphicsadapter=2 (search “rhi” in your Output Log to find the GPU adapter number). If GPUs are from different vendor, you can also use: -prefer{AMD|NVidia|Intel}. In my case, I prefer AMD iGPU to Nvidia GPU for better cooling on my laptop in the summer. So I use -preferAMD.
