As the title says I have just installed 4 gigs of ram in my late 2009 macbook pro about 2 minutes ago and immediately noticed a difference. I am very happy with the ram A+. It is the Crucial 1066 mghz 2x2gb sticks of ram ordered off of amazon for $100.00. If you have an extra benjaman burning a hole in your pocket, this is the upgrade for you. you WILL notice a speed increase, and it is very simple to do!!