If you are doing serious Deep/Machine Learning you often get massive datasets, you might need to pre-process substantial portions of them for different models y

If you are doing serious Deep/Machine Learning you often get massive datasets, you might need to pre-process substantial portions of them for different models you want to try, you might want to do custom models that are trained e.g. on 4k/8k video footage (think DLSS, self-driving car or drone footage); space gets exhausted pretty quickly. You might also want multiple independent drives, as you might do this all in parallel and it would be too slow to do it on a single drive at the same time, and even RAID with two drives would have a large performance penalty for seeks.