why cpu faster than gpu?

My matlab version is 2022a. I ran the DDPG of 'SimplePendulumWithImage-Continuous' for 50 epidodes with

criticOptions.UseDevice = 'cpu';actorOptions.UseDevice = 'cpu';

and

criticOptions.UseDevice = 'gpu';actorOptions.UseDevice = 'gpu';

Surprisingly, it took 712 seconds for cpu and 1202 seconds for gpu. How did this happen?

The cpu is R5800H and the gpu is 3070 max-q.

[Joss Knight]

Is this a laptop?

[Hu Keting]

Yes. The power limit of CPU is 45w while the GPU is 140W.

[Joss Knight]

We're looking into it. It may be that this example isn't complex enough to get a benefit from the GPU.

Answer 1

[Vidip Jain]

In the case of the DDPG algorithm for the 'SimplePendulumWithImage-Continuous' environment, the performance may be influenced by the size and complexity of the model, the number of episodes, and the batch size used during training. It is possible that the CPU in your system is better suited for this specific task than the GPU. This can happen if the GPU is not fully utilized during training due to factors such as small batch size or insufficient parallelization. In such cases, the CPU may perform better because it is optimized for sequential operations and can better utilize the available resources for this specific task.