i know its a HD 5850 it says VTX 3D on the fan Clocks are 765/1125 default the top of it says ATi Radeon
im looking to crossfire so ill need to know what to buy
Any 5850 should work fine, you can either find a gigabyte or asus OC version with the 765/1125 stock clocks, or you can buy any card and set it to the higher clocks manually