That's interesting, because if it's the WD greens, I have 4 of them (all 1TB), and all have the same issue: they power down constantly, and then are a real bear to spin up again... it takes 20-30 seconds before they spin up... drives me crazy. Of course, I got them in WD MyBook enclosures, so maybe that makes a difference, but I got my music on them, and it takes forever to kick in once I select a song. Sucks.