Your post indicates you have the same problem with two drives. Both SATA.
Positive areas of interest:
A software update that altered the SATA drivers.
Partial failure in the PSU.
Some kind of Malware.
Last, but not least;
- component failure on motherboard, e.g.m faulty capacitor.
Now of the above are likely, so here come the questions about did you move the computer, was there an electrical storm, did mice get into the PC case?
Best guess is your CD/DVD drive is failing and it contaminates the power supply lines. Excessive current, and high electrical noise. That is a very wild guess, but statistically, CD/DVD drives fail more often. Easy test is to remove all cables to the CD/DVD.