That picture was very helpful, the PCIe x16 BUS is black or another odd color while AGP is BROWN. Besides, the x16 PCIe is LONGER. As far as a GPU goes, I would recommend upgrading to the 6800GT or Ultra AGP version, or maybe the x800, the x850 is OVERKILL on AGP BUS... It just puts out too much for it to handle. Go with an x800 or 6800GT/Ultra for the budget. What are you looking to spend? AND DO NOT USE BEST BUY, I WORK THERE, WE CHARGE WAY TO MUCH!!!