i have a cq3041in pc and want to buy a graphic card to play london 2012 or arkham city ... what are the cheapest graphic card which will be compatible with my motherboard and will allow me to play these games
With only a 180W PSU, you will be limited to a card that doesn't require a separate PCIe power connection; i.e. one that gets all its power from the PCIe X16 slot (75W).
One of these HD 7750s would be the max you can go. The HD 7750 maxes out at 55W. http://www.newegg.com/Product/ProductList.aspx?Submit=E...
You could also go with an Nvidia card, but they have nothing that can match it that doesn't require a power cable.