Are you prescient? Anyway, best speed improvement is to go with SSD drives instead of mechanical. Get the fastest you can, use mechanical drives for external use. No more defragging to worry about with SSD.
I don’t have pure SSD’s but i do have a hybrid mechanical drive for (C).
Check to see if i need to defrag and it always shows zero percent for C drive. I’m on Windows 10
Since Macbook ‘13, Apple uses SSD devices which connect at PCI-e speed (M.2) vs most PC which connect at SATA rates
Critical matching is required to make it work but it is MUCH better than SATA