The limits aren't going to be based on the processor. It's going to be based on the motherboard and what it can handled. From what I have read at the HP website, the Pavilion 307x has onboard graphics but also has an AGP 8x graphics expansion slot. This slot gives you plenty of options to choose from. Some of these boards do have certain requirements that you need to make sure you meet before purchasing it. Also, if the system is set up to use the onboard video port, you may have to go into the bios to disable the onboard video. (I also couldn't find information on that at the website either.) If there is nothing in the bios about disabling the onboard video, then it may happen automatically once the agp board is installed.