I currently have 4gb in my MBP 13.3 Early 2011. Would upgrading it to 8gb make any difference in gaming wise for example Diablo 3? Also, what brand of RAM would you recommend? Also, what types of problems might I run into while doing this? Also, it won't void my warranty, would it? Bought December 2011. Switched from PC to Apple. Would this work fine? http://www.newegg.com/Product/Product.aspx?Item=N82E16820139985 Suggestions wanted! Thanks!