Hi. I recently purchased an HP P7-1225 desktop. I saw that you can increase the graphics power by using dual graphics mode with the APU on the AMD site, but theres a thought on the back of my head that's confusing me, I want to add a 6670 to use the dual graphics mode however I only got a pci x16 slot and not a 2.0 slot do I need to upgrade the mobo with one that has a pci 2.0 slot or will the pci x16 slot work just fine dual graphics mode? Also my APU is the AMD A8-3820 which is not listed on the site but the Radeon 6550D which is the CPU's graphic is. Will that affect dual graphics mode? This is the computer I purchased.
PCI is forward and backward compatible. Whatever you stick in will work at the highest speed both MB and Card support.
Look at cards other than a 6670. Getting the APU to help the graphics card is nice, but if you want good gaming graphics you'll want more than a 6670. (if your budget just covers the 6670 you'll find it's much better than the APU graphics).
You have a 300w power supply: Total wattage: 300W That will support about 100w of graphics. Something like an HD7770 will give you a lot of gaming w/o needing a new power supply. HD7770 uses 80w max. The hd6670 is about 63-66w.