I have a Dell and was wondering if there would be a notice in performance if i get Gaming Memory. I see this will fit mine OCZ Gold Series 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 667 (PC2 5400) Dual Channel I have 4GB now but what came with it. Another ? is can i have 2GB gaming memory and 2GB of the stock Memory in at the same time? Thanks