Is lightning.gpu really faster than lightning.qubit?

I have been using lightning qubit before in my hybrid neural network with 10 qubits and 100 epochs and it only took me 1.1561 hours for the execution, but when I changed the simulator to lightning.gpu, it took me 18 hours to simulate it. Also, I am using one NVIDIA GeForce RTX 3080 cores with 10GB of RAM and when I run the program the utilization runs up to 60 percent.

Hi @aouie,

lightning.gpu can have some large overheads in time for small numbers of qubits. For around 20 and more qubits then you can start seeing a performance improvement in using GPU vs CPU.

I hope this helps!

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Thank you for clarifying this one, I also checked everything especially the cuquantum and cuda, but it works just fine. Your answer is really helpful!

Iā€™m glad @aouie! Let me know if you have any further questions.