I had an extra comp HP Elite 8100, it has a PCI e graphics cards slot so I shoved a card in there... but found out there is not enough power from the power supply. I bought a power supply, found out the pins on the HP were non standard, so I shoved a power supply tester on the new PS and am powering the graphics card from an external power supply :p

Could it damage my machine? possibly? Shrug, I'm doing an extra 300Mh/s so I figured what the hell