years ago, my iMac was running craaaaaazy slow. it was pretty much unusable and seemed like anything that touched the disk took minutes instead of milliseconds. initially i thought it was from a macOS update (like maybe they didn’t bother testing on spinning disks anymore and just let things become unusable on old systems) but eventually realized it must be a problem with the hard disk drive.
all the disks i’ve had die in the past would make crazy noises leading up to an eventual complete failure. so this drive is quite strange with its S.M.A.R.T. data being fine and reading and writing working properly, but it just does everything 100X slower than it should. 🤔