A Mach3 computer does not require 4 gigabytes of ram.
A Mach3 computer should be dedicated to your CNC machine.
It should not serve dual purposes, IE cad design machine and CNC controller.
If Mach3 is interrupted by another software operation while it is running a CNC machine it may cause a malfunction which could be either dangerous, lethal and or or may ruin the part it is machining.
Mach3 needs to be an exclusive application while controlling your CNC machine.