Pushpak_1 :
herrwizo :
You will need a quad core to use full potential of that card. Q6600 is recommended. If your motherboard supports Q9550, that would be even better (which mobo do you have?). On such low resolutions you can expect high details and good framerates in most games. Just make sure that you have enough memory - the minimum should be about 6GB, preferably 8.
I'am not sure about motherboard model number but it has LGA 775 socket
get CPU-Z or Speccy and runs it it will tell you what you got under motherboard information.
CPUZ web page http://www.cpuid.com/
Speccy web page
https://www.piriform.com/speccy/download/standard
just copy and paste, upgrading cheaply to a q6660 to even QX9350 (like 100$) would renew that old desktop
but I would only do it if the motherboard can handle more than 4gb.