I got this problem. My secondary drive (hdd, WD10EZEX 7200rpm, not os-drive) reaches 100% usage ONLY after 3/4 hours of gaming, and then when this happens, after 20/30 it has some spikes (sometimes it takes 100% usage and sometimes 0-5%). When this happens, programs won't neither open nor close, file explorer has many visual glitches, everything's much slower and a pc reboot takes too long (I actually haven't let it finish a reboot in a while, once i waited for 20 minutes and the pc still didn't reboot). I did a benchmark on HD Tune Pro 5.75 and on CrystalDiskMark, these are the results (https://imgur.com/a/SkoJr7U).