Hi guys, I am thinking of buying WD Caviar Black 1TB. My current HDD is so slow and very low on space. Pardon me, I am VERY noobish regarding HDD. What I want to ask is, is it okay to let my old HDD contain the OS? In order to play games more efficiently, do I have to set the WD Caviar Black as the one containing the operating system? Or do I only need to put my games files on the WD Caviar Black in order to play that particular game efficiently? Thanks in advance.