Doubling your ram will increase overall pc performance, read/write times and how fast your computer can handle applications and more of them. The more ram the more you can have open and actively be working on. Like stated above 32 bit systems are capped at 4gb, 64 bit you can go to the sky. It will help applications like normal day to day Web browsing while running programs and especially ram intensive programs like photoshop and video editors ...ect it will also help with games that use a good amount of memory like bo3 and fo4. The newer games need lots of ram. 8gb is the standard for any gamer to have on his pc