The GPU volatile-util is still varies from 2 to 4 %. Here is my dataloader. (opt.batchSize = 32)
train_set = datasets.VCTK(root = '/home/.../dataset/dataset_training', download = False, transform = transforms.PadTrim(max_len=30000))
training_data_loader = DataLoader(dataset = train_set,
                                  pin_memory=True, num_workers=8, batch_size=opt.batchSize,shuffle=True)

Are there any suggestions to fix it?