monai.transforms.RandZoom is slow

[NinelieAimer]

When augmenting 3D medical images with RandZoom in MONAI, I'm experiencing slow processing speeds. Despite using CacheDataset, the GPU utilization remains low. However, this issue doesn't occur with other augmentation methods.

[KumoLiu]

Hi @NinelieAimer, it's reasonable that RandZoom (including interpolate) slower than other augmentation (such as RandFlip). And CacheDataset will not cache random transforms.

MONAI/monai/data/dataset.py

Line 704 in 8e134b8

Dataset with cache mechanism that can load data and cache deterministic transforms' result during training.

[NinelieAimer]

Thank you for your reply. Are there any methods to expedite the training process? The current duration is quite lengthy.

[KumoLiu]

Hi @NinelieAimer, you could refer to this tutorial such as using multi-threads ThreadDataLoader.