Hibernation.
Win7, Win10.
It's quite common for mining rigs to have "small" SSD, just enough for the OS and Claymore, so probably doable on a 64GB SSD even.
I'm running win7 (w/o hibernation), claymore and very little else on a 40gb ssd. It all just fits, but again, one of those things that was lying around and had no other purpose.