I have an old 120gb Samsung 840 EVO SSD where i have my OS (Windows 10) installed. I've had this for close to ten years now with no issues.

I also have a 1tb 850 EVO SSD just for gaming.

Recently i bought a 1TB M.2 NVME, new RAM, MOBO and CPU, GPU and after a while i started experiencing some weirdness.

Namely, my EVO 850 completely dissapears from my system. Like as if it wasn't there... Cannot be detected by anything, only in the BIOS. The M.2 however, remains.

It took me a while to figure out how to get it back reliably, and it requires me to let my PC go into sleep mode then turn it back on, in which case i always get it back. But if i simply restart, or shut my PC off manually, it dissapears again until i put it into sleep mode then turn it back on. Taking out the CMOS battery also works but the same thing happens. It doesn't matter if the battery is in or not, after a manual restart, it dissapears completely. Outside of that, i can access everything on the drive and it seems to be working fine.

I *could* live with this, but after a period of using my computer, i start to experience small stuttering. Like, even if i'm not playing games, just listening to youtube, i get this micro stuttering. Restarting my PC fixes it (for a while). It doesn't seem to come back with just the M.2, if i don't put my PC into sleep mode to get my 850 back.

Games also started to randomly crash my PC, though not too often. No BSOD, instead everything simply freezes and my PC restarts itself (making my 850 EVO dissapear once again.) This might have been related to my old GPU since it died a few days ago but i don't know at this point.

Could the M.2 be interferring somehow? I have since tried it in every slot (i have 4 on my MOBO) as well as trying different sata cables and ports for the 850. Nothing worked. I even did a complete and clean reinstall of my OS (though i did not wipe the 850. Should i? It only has games on it)

I even changed the PSU. Nothing.

I checked the drive health with EaseUS and both drives show up as "Good". The 850 has 98% and the 840 has 53% status. The built in Windows tools to check for drive health also show them as good. Could the 840 with my OS on be dying? Should i completely reformat the 850? Maybe flash my BIOS or something somehow? I'm pretty clueless when it comes to that sort of thing, i seem to be on the latest firmware though.

I'm stumped. Please help me or give me some clue as to what could be happening.