Contents:

• dataloader (num_workers)

Dataloader (num_workers)

Try to customize your DataSet and DataLoader following the PyTorch style to benefit from the multiprocessing.

Number of workers (multiprocessing)

grid search for the best number of workers for the train and test dataloader. For example, using workers from 0 to 32, measure the time for each number of workers.

import time
for num_workers in [0, 1, 2, 4, 8, 16, 32]:
    start = time.time()
    train_loader = torch.utils.data.DataLoader(
        train_dataset, batch_size=batch_size, shuffle=True, num_workers=num_workers)
    end = time.time()
    print('num_workers: {}, time: {:.4f}'.format(num_workers, end-start))