I recently upgraded the RAM in my 2009 unibody MBP. It was super easy and I'm really happy with it. However when I opened up the computer I saw that the inside had a lot of dust. Unfortunately I didn't have compressed air on me at the moment to clean it out, but I was thinking, is this something that would perhaps be slowing the computer down? I.e. if the dust is reducing the ability of the fans/heat sink to circulate heat out of the computer the overheating would cause the CPU to throttle.