I wonder if there are a better tool than the panel at System → Preferences → Power Management to manage the power consumption for the HDD. Specifically HDD in a laptop.
You can experiment a bit with a few options for
I don't report here how the value should be chosen, I let you to read it from the man page.
That said, I would NOT recommend to choose timeout values too short, as still one of the most stressing times for a hard disk is the spin-up time, i.e. it's better to leave a HDD spin a little longer while idling than continuously turn it off and on, especially with modern, low-power HDDs.