Lightning.gpu doesn't seem to use GPUs

Hi @psansebastian,

Thank you for your question!

We released a new version of PennyLane recently so it would be best if you could upgrade to the latest version.

You can try creating a new virtual environment with python 3.10 and installing PennyLane, custatevec and pennylane-lightning-gpu as follows:

python -m pip install pennylane custatevec-cu11 pennylane-lightning-gpu

If you want to use your existing environment you just need to add --upgrade at the end.

I also see that your CUDA is version 12.3 so I would recommend going to version 11.8 or following the instructions here if you want to stay in version 12.

Note that lightning.gpu only supports NVIDIA gpus with SM7.0 or higher so it’s possible that your GPU isn’t supported.

Please let me know if you have any additional questions! I hope this helps.