No gaming software uses your full RAM.
If at all, it's reserved half of it unless you enable a 3GB-Switch or assign more memory by other means. However, that does not necessarily increase performance.
In general, Windows offers 2 GB to any application, no matter if you have 4 or 64 GB of memory installed.
Only exception is a 64bit.exe running on a 64bit OS. In this case, it CAN use more RAM. But again, this will not increase overall performance. If you notice a difference, it's by improved loading times and less texture-loading while inflight.
|