I am running a Macbook Pro 15" 2.8ghz with 4gig of ddr3 For the last 6 month or more my computer have been running awfully slow from time to time. The CPU can usually run at 80-110% and for exampel firefox can use 70%+ and slowing down my entire system. The issue stops me from running multiple application and i that can't be right with a 2.8mhz and 4 gig of RAM. Also the computer can run real hot sometimes well over 100 celsiuce What could be causing my problems? Edit: I usually 30 gig of free harddisk space on my harddrive.