This is in my 13" Mac Book Pro (new style). If I take a 320Gig 5400 RPM drive and replace it with a 1T 5400 RPM drive will this effect the power usage? Same brand of hard drives, just a larger size, I had switched to a 7200 but my battery life has been allmost cut in half, I know that the speed of the drive will effect the battery life but I am not sure about the acctual size using more power. I'm lost on this one.