32GB RAM is enough for single GPU training.

Yes, 32GB is plenty. Your GPU memory is the bottleneck, not system RAM.

The only time 64GB helps is if you’re loading a massive dataset entirely into memory instead of using disk streaming or memory mapping. But even then, it’s a convenience, not a necessity. Most ML frameworks handle data loading efficiently.

Unless you’re training on a multi-hundred-gigabyte dataset that must live in RAM for some reason, save your money and put it toward a better GPU. That’s where the real performance lives.