I've decided to upgrade my computer's RAM to 4GB DDR3. Now, I know this is more than enough for Oblivion, but how about other and upcoming games? Since the members of this website are very friendly and helpful, I hope it's okay that I posted this here. Games that I'm hoping to play are Mass Effect 2, Bad Company 2, Mass Effect 3, Fallout 3 and New Vegas, GTA IV, and Dragon Age Origins. I know absolutely nothing when it comes to this stuff, so thank you all very much if you help! :foodndrink:

What operating system do you have? If it isn't 64 bit, your machine will only be able to use around 3.2gig of your RAM. Should be good for most games coming out in the next year though.

Well, we need to be sure that your PC even supports DDR3 because it doesn't sound like you'd know. Please post a dxdiag so we can see your specs:
Start - Run (if Vista, the search box acts like Run) - type dxdiag - hit Enter - "save all info" button - open txt file and copy/paste EVERYTHING here

Picture of process: http://www.windowsresource.net/cimages/gotodxdiag.jpg

I have Windows 7 Home Premium 64 bit. I also have a AMD Phenom II x4 cpu.

That's fine, but what is the make and model of your motherboard? There are AM2+ motherboards that supported AM3 CPUs. Also, there are Phenom II X4 chips that were made for Socket AM2/AM2+ platforms. Several of these motherboards use DDR2 RAM as a standard. AM3 motherboards use DDR3....just want to make sure you have one and also to check support and compatibility with speeds.

Regardless of what OS you have, programs have to be written with a 64 bit architecture in mind to make use of more than 3 gb max. With the majority of computer owners still using a 32 bit OS, that's not going to happen anytime soon. So having 4 gig of RAM will be more than enough for any game at the moment. All those games you mention are 32 bit programs so you'll be fine. In fact, I don't know of any games right now that are exclusively 64 bit and it's just not cost effective to have two different versions. Even 32 bit programs require a special bit of code to make them Large Memory Address aware to make use of the 3gb I mentioned. By default, they will only use a maximum of 2 gig.