Multi GPU Raytracing - how to activate (should be in lowlevel in 4.23)

Hey guys! we got two titan rtxs in our office. i would like to test rtx with multigpu, which should be available since 4.23, as stated here Real-time ray tracing in Unreal Engine: Part 1 - the evolution - Unreal Engine
“the low-level support added in 4.23 offers control over which GPU will render a certain pass”
but i cant figure out, how to actually set a gpu for desired rtx pass?
would like to have some clearence here
best

This is interesting to me too

really high priority issue here. without multigpu support to overtake some raytracing passes, its really not useable for now for bigger scene. we would profit extremely from that feature. please someone from epic, @**Juan Canada **clarify on this

I would also like to know more about how this is configured and used in an Unreal project - anyone?

That’s not what you’re wanting, that low-level multi-GPU support is for some programmer use. The full multi-GPU raytracing is coming later.

Can you already give information on when it’s going to be possible to manage ray tracing with multiple GPU’s? I’d be really nice to use one GPU for the UI, and the other for the ray tracing. Another question: Are the Quadro RTX Cards performing better than let’s say a 2080ti when using RT GI? Thanks

I don’t know what all their plans our, the multi-GPU solution for RTX is coming later–if it comes at all, since multi-GPU features for game engines are very rare. I would expect that most likely it would simply allow a higher amount of rays for raytracing, so you could double the quality
As far as how Quadro compares, the Titan RTX is about the same as the Quadro 6000 but it’s more than $1,000 cheaper. The main advantages of the Quadro cards is not for games, it’s for CAD software.

1 Like

So, is multi-GPU real-time (ray tracing) still not available in unreal? Last time I remember, I connected two Computers, each has an RTX GPU (3090) and used nDisplay plugin to visualize over 4 monitors (2 for each). It was working.