Your program is “running incredibly slowly” because it is thrashing horribly ... and it's never going to get better. You're either going to have to re-design your algorithm or acquire more physical RAM for the box.

In operating-system circles we speak of a process's working set, this being the (constantly changing) set of 4K pages which the process needs to have in-memory in order to run without delay. The working-set size of any process needs to be a manageable fraction of the total virtual-memory space, and the working-set needs to be fairly non-volatile, that is to say, once the initial pages have been paged-in the amount of page-replacement activity needs to drop.

A program with a 10GB “footprint” is either going to have to be re-designed, or run on a machine that has 15GB or 20GB of physical RAM. Yes, this might be a case where the right thing to do is to “throw silicon at it,” and if that be the case, make it so.