How come the GPUs aren't doing any work?

[akashi1]

I even switched my monitor to run off of the CPUs built in GPU, so the GPUs aren't doing anything. Thanks!

[vladimir.nedev]

You have to switch the mode in Task Manager to "Compute_0", not "3D".

Greetings,
Vladimir Nedev

[akashi1]

So you are saying the GPUs were working?

[vladimir.nedev]

Sorry, didn't see it was doing the Light Cache pass. The Light Cache pass is computed on the CPU as far as I know.

But generally, the V-Ray GPU activity won't show in the "3D" section in Task Manager, it shows as 'Compute_0".

Greetings,
Vladimir Nedev

[a7az0th]

I wouldn't trust the Device Manager for showing proper GPU usage.
You can try the NVidia provided tool called NVSMI. It can be found alongside your NVidia Driver Installation here:
"C:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi.exe"

To run it, open a terminal (Start Menu -> Run -> "C:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi.exe" -l )
The -l option is important, it tells the tool to 'loop' and refresh the measurements every 1 second
It gives you precise usage info, GPU temperature, VRAM usage, etc.

Looks like this: