jeffmcclan's Profile

The article leaves omits one important item - for maximum performance the 2 memory modules must of identical size and speed (2 x 512MB 667MHz, or 2 x 1G 667MHz). With same size modules, all Intel based Macs runs with double the memory bandwidth (like twice as many lanes on a freeway) - thus memory access is twice as fast. Anyone installing mis-matched SODIMMs (512MB + 1GB) with gain from the additional memory but will run AT 1/2 THE MEMORY SPEED. Thus, it is not suprising that notebook speed increases greatly with a second 512MB installed. (One final note - all of Apple's shared video models, Mini and iBook, ship with 2 identical SODIMMs installed for performance. Other models usually ship with one so customer can upgrade as needed.)