OK, so I have a new render box set up with a new Nvidia RTX A6000 GPU and I wanted to goose up our KeyShotXR renders which can take a bit of time to complete. The old render box had the previous generation RTX 6000 GPUs. Here's the issue: If I put all three GPUs in the box and enable the two older ones it actually dramatically SLOWS down the rendering process. Is it just not possible to mix these models? Kind of depressing if that's the case.
Aye, young lad, ye happen to stumble upon the bane of GPU rendering. Should it work? Yep. Does it work? Sometimes.
People will suggest to update drivers, match drivers, roll back drivers, delete drivers, reinstall drivers. ad nauseum. GPU rendering just isn't as stable as CPU rendering. Is it getting there? Yep.
So, there is probably some reason that cards of different generations of hardware won't play together nicely in the same sandbox, it might be due to bus speeds, might be due to which slots the cards are in, might have to tweak the slot settings in the computer to match the bus speed of the card, stuff like that. Hopefully someone from Luxion will chime in and tell you which checkbox to click to make it work and its that easy, but after 8 years of reading and researching and playing with both CPU and GPU rendering, this is the reality of it right now, what you are experiencing. Man that would be cool to get all those cards cookin and be able to bake out some renders dang fast. You'd get to the point where it takes longer for the system to set up and distribute the work and stitch it back together than it would take to render the image!
I've seen some Unreal Engine realtime stuff that would 100% be good enough for our product renders, but the UI is not the greatest and the learning curve to get to those is way beyond my capabilities right now. Hope KeyVR gets there at some point :)
Good luck and if you figure it out, please post the solution, there are many more that would want to do this, and with the glut of used high end GPU cards that will hit the market in the next year or so, this could be a big thing.