can GTX and RTX render using RTX engine?

[fraggle]

Hello, just wonder if the PC got 2 graphic card, old version like GTX and new verison RTX, can the render engine be RTX or should it be cuda?
Thanks

[Joelaff]

Pretty sure you have to have an RTX card to use RTX, but they can both do cuda.

However, one RTX might be faster than the two in cuda depending in the scene.

[Muhammed_Hamed]

Hello fraggle

We don't recommend mixing GTX and RTX cards in rendering with V-Ray GPU, specially if your RTX card is a high-end one like a 3080/3090
What you can do is use your GTX card for your monitors and viewport performance, so all the VRAM and performance of your RTX card is dedicated to GPU rendering

To do that you will need to connect your monitor(s) to the GTX card, then go to control panel and change OpenGL Rendering GPU to your GTX card



This makes a big difference on both performance and memory usage, you can also set your Denoising Device to the GTX card in the device selector. In this case I have 3 monitors connected to my second 3090, indicated by the 3 (***)



That being said, Pascal and Maxwell GPUs can use RTX mode through software raytracing. You will not see much of speedup this way, compared to Hardware-raytracing present on Turing, Ampere and Ada Lovelace GPUs

Best,
Muhammed

[fraggle]

Thanks, that's a very clear explanation, I dream of having 2 x 4000 RTX.