@AriShadowZ Just at a guess, is this a laptop/pre-built system?
The reason I'm asking is that you say you have 12 gb of RAM - that's usually something they do with laptops and prebuilts, and a certain amount is going to be shared video RAM. So - with 12GB RAM - you've probably got 8GB for the game/OS, and 4 for whatever graphics chipset you have.
The minimum requirements when the game came out was 8gb of system RAM, and at least 2gb of video memory.
That's why it's maxing out your ram - it's using whatever your laptop is telling it to use. My advice would be to max out the memory that your system can use. That way - if you say go to 16 or more GB of RAM, you'll be over that 8gb minimum requirement, and you may find it works better.