iMac hard drive spins during standby

[dhokes]

When I put my iMac in standby mode, the hard drive spins every couple of seconds. Why is this and how can I stop it?

My Energy Saver options:

• Put hard disks to sleep when possible (checked)
• Wake for network access (unchecked)
• Start up automatically after a power failure (unchecked)
• Enable Power Nap (unchecked)

System:

• iMac (27-inch, Late 2012)
• 3.12 TB Fusion Drive

Hmm. So if I unplug my USB hub from my mac (Skiva Octofire Multi USB Charger) even though it doesn't have any devices connected to it, my hard drive doesn't spin during standby.

 

[satcomer]

Because the consumer drive is writing to it's cache before sleeping!

In your case it seems that don't recognize Mac OS Sleep command! That's what you get with a cheep external!