The game ran horribly despite me having plenty more RAM to be allocated, it was clear that the issue was that the game didn't have enough memory to work with. It was just lag getting worse and worse until the crash.
The only way you can have not enough memory is for the game to literally start using paging file but that can only happen if your RAM is full. If your memory is not full then it's either CPU or GPU problem. No program is going to lag because of not enough memory unless the computer has to do transfers from slower memory.