@AmiKit
Have you ever updated the firmware of your HDDs?
No.
Firmware of my HDD is 3.AFE
My ST3320620AS has 3.AAK
The SeaTools for Windows reports that "Mandatory Power Management" of my HDD is enabled.
Same here, so this isn't it.
Are you absolutely sure the drive actually spins down? Maybe you mistake some of the head movement sound for parking? The Seagate drives are
really quiet these days, and it's quite hard to spot if the drive is really spinning or not.
Also, in an attempt to avoid heating up the R/W head (or the platter below, I can't remember which exactly) the Seagate drives periodically seek the R/W head around the disc, even when idle. This creates audible "clonking" noises from the drive. Perhaps you're mistaking these for parking?
