Very surprised UE 5 isn’t using more than my primary GPU for VRAM and overall processing etc. I’m coming from years of working in Davinci Resolve; each identical gpu added to the machine (without SLI or NVLink or anything like that), the system performance instantly increases by around 40%. DR will make use of the 2nd GPU VRAM and overall processing power.
Will UE 5 have the same capabilities?
I see my CPU usage absolutely max out in UE 5 - same with system RAM and VRAM on GPU 1.
But GPU 2 is untouched… GPU 1 is doing essentially ZERO processing, maxxing out VRAM, and GPU 2 with zero VRAM usage and zero processing…
Is there a plugin or something I can install to actually utilize all this hardware sitting here?
I get that PUGET SYSTEMS demonstrates that money is currently better spent on a 64 core CPU. But the performance gains I experience in Davinci Resolve with multiple GPUs is what I was expecting in Unreal Engine, especially this latest release.
I want Multi-GPU support for UE5 as well. I want to be able to just add another RTX A6000 to my workstation when I want to upgrade instead of basically having to buy a whole new computer to upgrade.
Can anyone from Epic shed some light on multi-GPU plans for UE5?
I’m in the same boat, I have been trying to get Multi GPU running in Unreal since UE4 and it still not looking great in UE5. From my research there is a couple of commands targeting DirectX 12 mgpu but the engine just crashes when used in conjunct with ray-tracing or Lumen. The commands I found must be run on the .uproject which are:
“-game -d3d12 -MaxGPUCount=2 (or number of GPUs in your system up to 4) -AFR”
and if you want to test a multi GPU setup with a single GPU system you can add -VMGPU. I also found these console commands that you can add to your ini config file:
r.AllowMultiGPUInEditor 1
r.EnableMultiGPUForkAndJoin 1
r.PathTracing.GPUCount 2
D3D12.AFRSyncTemporalResources 1
D3D12.AFRUseFramePacing 1
r.GPUParticle.AFRReinject 1
An example if you want to try it on your system is to run this in CMD (Command Prompt):
Also go to your project config folder “C:\Users\Public\Documents\Unreal Projects\UE5Test\Config” then edit DefaultEngine.ini if there is no [/Script/Engine.RendererSettings] section add it and the add:
Added support for multi-GPU rendering (mGPU). SLI is required. To enable it, pass -MaxGPUCount=2 on the Unreal Editor command line and set r.PathTracing.MultiGPU=1, which can be toggled at runtime. (r.AllowMultiGPUInEditor=1 is no longer required in .ini files to enable mGPU in the editor.)