Quadro RTX 4000's GPU does not working with RTX A4000?

[izumi_kobayashi]

I have Quadro RTX 4000 and recently add RTX A4000 for Vray rendering. RTX mode gets really faster but when checking task manager, I found that 4000's GPU is not working but only memory is used. Is it normal? If both GPU contribute to render, does it get faster? Is there any settings to do that?

Rhino 7 + Vray 6
Quadro RTX 4000 + RTX A4000
Driver version 528.24

[Muhammed_Hamed]

Hello izumi_kobayashi and welcome to the forums

Task Manager doesn't show correct monitoring for GPU usage, use other tools like MSI AfterBurner or GPU-Z
Don't worry, your 2 GPUs are working well together. But Task Manager doesn't show correct usage for Compute tasks like GPU rendering

Best,
Muhammed

[izumi_kobayashi]

Thank you Muhammed! I confirmed both working well by GPU-Z. One more thing, when I visit https://www.chaos.com/jp/vray-gpu, it says "Recommended NVIDIA driver for V-Ray GPU is version 526.98". Should I downgrade it?

[Muhammed_Hamed]

Yes, you need to downgrade it to our recommended driver
Choose Custom Install, and check Clean Install Checkbox. Then restart the machine

Best,
Muhammed