Switching to process Pool might be a bit of an overkill here (I think)
wdyt?

It uses only one CPU core, could I use multiprocessing somehow?

Hi EcstaticMouse10
Hmm, yes it should be multi core:
https://github.com/allegroai/clearml/blob/a9774c3842ea526d222044092172980ae505e24f/clearml/datasets/dataset.py#L1175
wdyt?

I don't know, why it uses only 1 core.