I have a 20'' Intel Core 2 Duo iMac. I bought it at a store, so it came with the regular options (meaning I have 1GB of RAM.) I was thinking of upgrading it, and buying 2 memory sticks of 1GB each, for a total of 2GB. Will there actually be a noticeable difference in the speed? Programs opening faster, Photoshop not taking the time it's taking at the moment to load and do regular stuff?