I am currently running 9400 gt and playing games like dirt 3 on low in 1024x768,and i really want to upgrade my Gpu
the specification of my cpu are as follows -

Mobo - G31M-S2L
CPU - Intel Pentium E5300
Psu - 280 watt (going to get a 400 watt)
Ram - 2 GB DDR2

i was planning to get the HD 6670. Is it any good ? Will it be compatible with my rig ?
( i am worried about the compatibly issue because i am unsure of my PCI-e version and if that will be an issue)


Please recommend suitable Gpus which will be compatible with my system.

Thanks

Well I don't keep up on how the graphics cards compare to each other however you do have the correct pci-e slot. You will certainly need a stronger psu and you'd probably need more than 400 watts.

Also consider that for computer parts you get what you pay for. If you can't spend even $100 then you might want to wait until you can.

i am worried about the compatibly issue because i am unsure of my PCI-e version

Then look it up! Plug g32m-s21 specifications into your favorite search engine and learn the specs for your motherboard. It has a PCIe x16 slot. Note PCIe v2.0 cards are backwards compatible to the PCIe v1.x your motherboard most likely supports.

Do NOT select your power supply until AFTER you have selected your graphics card. Buying the PSU first is putting the cart in front of the horse - and not knowing what's going in the cart. Select the graphics card (and any other HW upgrades or additions) first, then determine your PSU requirements.

It is too hard for any one person to stay on top of advances in graphics. So I recommend you read Toms Hardware - Best Graphics Cards for the Money, August 2011.