Multiple GPU usage

[Luma3d]

Twinmotion just did a live stream talking about their next update for their real-time software. One of the features is the ability to use multiple gpus to render their pathtraced images and animations. Is Vantage team looking into adding that feature to their toolset?

[Alexander.Atanasov]

Hi Luma3d,

Chaos Vantage currently supports up to 2 GPUs. However the scaling is not linear and depending on the scene may not see a significant increase in performance. We will look into improving this in the future.

Best regards,
Alexander

[Luma3d]

Coo..Last I checked, I couldn't select two gpus in Vantage. Has that changed? I have an external egpu with a 3090 and a msi that has a built-in 3080.

[vladimir.nedev]

Have you tried Edit->Render Devices ?
Vantage needs to be restarted after you change the devices there.

Greetings,
Vladimir Nedev

[npg]

We have disabled laptop multi-gpu setups with external+internal GPUs. Last we tried (long ago) it wasn't working.
There should be a warning like this in the debug log: "Ignoring additional devices due to hardware issues with external + internal GPU on laptops."

[Luma3d]

Thanks for the FYI...I also read in another post that it's still faster if you used the fastest out of the two GPUs vs. combining the two.

[npg]

If you mean 4080 would be faster than something like 4080+2070, then yes this is likely. But 2x4080 should be significantly faster than a single 4080. The other thing is that when using two GPUs it's better when the faster one is "primary" than the other way around.