Just bought a new HP 6200 desktop with a 320W PS. I swapped a GeForce 430 from my old PC to replace the onboard Intel graphics and was about to swap the OCZ Fatality 550W from the same machine to the HP. Low and behold, the HP doesn't have the 24 pin connector and it appears that the HP PS is somewhat proprietary (as are many Dells). My question is: can the 320W handle the NVidia 430 plus the DVD RW that I installed in addition to the DVD drive. Can I also install a USB3 PCIXP card?