Can you specify your system specs more ex. what GHz your cpu is running at what kind of PSU and wattage it has, and speed and type of ram ex, "DDR3"
Also if your thing about getting any new graphics cards you might need to get faster/more ram and possibly need to overclock your CPU to prevent bottle necking.
2.50 ghz 2gb ddr2 ram
1 gb asus gt210
psu iball lpe 223-400