Question – Does anyone here know much about HDD power management functions?

I’m puzzled by something. As the desktop PCs I’ve built over the years have steadily gotten quieter, the hard drive in my computer is an increasingly noticeable noise producer, its whine is easy to discern even with three or more other fans running.

In Linux, I thought I had set my drive to spin down automatically and I have heard the drive’s reduction in noise (sounding like a spin-down) making me think I had succeeded, but there was still an element of noise coming from the system I hadn’t really given much thought to even though it bothered me (with a bit of barely conscious background logic knocking around along the lines of, “but I heard it spin down so what else can I do”). Then the other day I pursued the topic again with a bit of Googling I found another setting which I thought I had done the command-line equivalent of, however when I tried it, the drive spun down and the resulting noise level was much quieter, as if my system had no HDD. Success!

The setting I just changed: Disks > Drive in question > Drive Settings > APM > Set to 127 “spin down permitted”.

How many ways can a HDD do power saving stuff? Do HDDs have multiple methods of spinning down, like running at a lower rotational speed being easier on a drive than a full spin down maybe? The Disks app > Drive Settings also has a ‘standby timeout’ setting in minutes which I don’t have enabled.

The drive I have is a Seagate Ironwolf (NAS) drive, ST4000VN008 in case that helps.