I've two external hard drives attached to my MBP Retina OSX Mountain Lion.
Whenever I open the Finder or switch to a Finder window, if either of the hard drives are asleep, there's a several second delay before the Finder opens while the hard drives whizz up.
This happens even if I'm not opening the hard drive folders at all. This also happens when I try to Save a file even when the default location of the Save dialog box is nowhere near the hard drive folders.
In the past few months, something similar has also started happening with Chrome. Several times, when I'm browsing, at various random points, there's a several second delay while something on the hard drives is accessed. This happens even if the drives are not asleep. When this is happening, I'm unable to use Chrome at all.
Note that unlike this thread, mdworker is not running, and Time Machine is not doing its backup.
What's going on and how can I fix these problems?