Hey all, I have a MacBook 1.83GHz, 512mb, 60gb that I got about a year ago...I have since upgraded the RAM. I'm looking to upgrade the hard drive. I've been checking around and found a good site, it looks like, for HD upgrades. http://eshop.macsales.com/item/Western Digital/WD2500BEVS/ My question: How many RPM is the hard drive in my computer right now? Will I notice a significant dropoff between 7200 and 5400?