i have an Acer Aspire (AM5201) everything stock. the graphics is only a 3450 256 MB so i decided to get a 4870 1 GB. I don't know if my PC has all the neccesary connectors, a "X16" graphics slot or if its a PCI based PC. Also I could use some help in choosing the right brand since there are abount 20-30 of them. Last, I don't know what power supply to get (want at least 650-watt in case I go crossfire in the future).