I have two questions. One, I have 2GB of RAM which came with my MacBook Pro. Can these be consolidated to one bank so that I can add 2 or for GB to the other? Or is that not how that works. I don't think it is but just checking. Also, what is the difference between these two RAM's? http://www.newegg.com/Product/Produ...crucial_4gb_ram_laptop-_-20-148-201-_-Product http://www.newegg.com/Product/Produ...crucial_4gb_ram_laptop-_-20-148-191-_-Product The only difference I see is that one is "204-pin" and one is "200-pin" but there is a 20 dollar difference. Also will these work on my MacBook Pro? It's a 15.4 in 2.5 GHz Intel Core 2 Duo and I have the 2GB 667 MHz DDR2 SDRAM running which came stock.