More than just on boot. For the brief time that I ran Win10 on an HDD, what it felt like was that the whole OS was almost constantly touching the disk, for what

More than just on boot. For the brief time that I ran Win10 on an HDD, what it felt like was that the whole OS was almost constantly touching the disk, for whatever reason, often blocking. Open start menu? Better do a bunch of disk I/O. Moused over anything? Touch the disk. Pressed a key? Hit disk. Doing nothing? Disk time! Whatever they're doing is probably fine, for very liberal values of "fine" (i.e. it's not actually fine and is probably harming system-wide performance and UX in more subtle ways, even on SSDs) for SSD-equipped systems, but made it practically unusable on an HDD.