Pennylane and Pytorch running on GPU

[antalszava]

Hi @Shawn!

For now it would be suggested to use the CPU with the TorchLayer from PennyLane. Although some examples might work, complete GPU support for the TorchLayer is something we’d have to further explore.

Recommend keeping an eye on the following relevant thread too:

Different interfaces, different performances

There is an example presented by PennyLane for qml.qnn.TorchLayer which I copy below. If one modifies only the interface line from @qml.qnode(dev) to @qml.qnode(dev, interface='torch') the convergence behavior drastically changes: for the case @qml.qnode(dev): Average loss over epoch 10: 0.1589 Average loss over epoch 20: 0.1331 Average loss over epoch 30: 0.1321 and for the case @qml.qnode(dev, interface='torch'): Average loss over epoch 100: 0.1709 Average loss over epoch 200: 0.1593 Aver…