For the last year I have been annoyed by my secondary hard drive taking 10-15 seconds to wake up every time I access it. I did some research a while back and through that came to the conclusion that it was the "Green Drive" that I got. Turns out it's a power setting.
To stop it from sleeping go to Control panel/ power settings/ then click change plan settings/ advanced power settings / choose the drop down under hard drives and change it to never. voila! No more sleepy drive.