I am pretty sure the card is not using 8+ watts when all the drives on it are idle...

I can't believe people are worrying about something less than 10 watts.

10 watts in constant use for a whole year is like $12 at the average electricity cost in the US.

I don't even let my HDDs sleep, the constant spin up and spin down and temperature cycle associated with puts way more wear and tear on them and would cause them to fail quicker and that is way more expensive to replace.

I have 20 HDDs connected to one of these SAS2 controllers in my home server.