Maximize memory available


I am interested in upgrading my system. I currently have a C2075 (6 GB mem) but with this GPU I am memory limited at the moment. So my question is what is the best course of action of maximize the amount of memory available for use – Dual C2075 or upgrade to a K10 (8 GB mem)? Will dual C2075 essentially double the amount of memory I have available, or will I have to separate my data in order to run my codes with > 6GB of data?

Any and all advice is appreciated.

K10 does not have 8GB of memory. It is a dual GPU card, where each GPU has 4GB.