Not sure. I experienced this personally using a picoPSU with spinning drives on one machine - no issues with spinup but silent data corruption on writes (which then got picked up by ZFS). Switching to a traditional PSU cured the problem.

Ok, I have running multiple machines with PicoPSU and never experienced this. In my opinion it is a pretty reliable consumer device.

However, thank you for pointing that out. I did not know that.

Can't say anything about picoPSU, except writing anything on RAID involves all the drives to seek and write and without a a solid power reserve you can receive a momentary dip of voltage which can lead for a malformed write, but back in mid-late 2000s I've seen enough HDDs failing and corrupting data which miracluosly behaved when moved to another machine or when you replaced PSU (with a decent one, not another $15 chinesium).

A lot of bad reputation of WD from that time is actually from the shitty PSUs, not the drives themselves.

Well, that's really interesting. If I ever experience these issues somewhere, I know where to start...