Will internal HDD spin down when a Mac is booted from another internal SSD? On my MacBook Pro, I am planning on removing the optical drive and adding an SSD to the mix. Since Apple doesn't support this configuration, I don't find any official documentation covering SSD in the optical bay or HDD in the optical bay.

I presume the energy saver setting would spin down any spindle-based drive when it's idle (like in a Mac Pro), but would like to ask others that may have experience with this configuration in a recent MacBook Pro.

When booted from OS X installed onto an SSD, will the internal HDD be spun down when not in use?
I had this setup for a while and yes, the hard drive in the primary disk bay would spin down when booted from the SSD. It was fairly easy to tell, because when accessing the drive there was a noticeable delay when first accessing the drive after leaving it idle for about 10 minutes. This was on an older machine (2009 MacBook Pro 15", running Mac OS X 10.7).