HI, I have a Mac book pro Its from 2011 i have the 2.4ghz intel core i5. I currently have 4gb of ram, but i really need to upgrade to 8. I think it will help my start up time and also my booting of programs. not sure if anyone can confirm this. Either way which ram from bestbuy can i buy that would work for this macbook? can i buy one 8gb ram chip or i need to buy 2 separate 4gb ram chips? thanks guys!!