The T7910 supports up to 3x 225w graphics cards in 3 slots.  So yes, your dual card upgrade should work with proper cables.[IMAGE]
Want to upgrade the existing dual Nvidia K5200 cards to dual RTX A5500 cards. The existing power supply is 1300 watts. I have dual 6-pin to single 8-pin power cables for the A5500. Will this upgrade work?
Dell Precision 7910 - upgrade dual K5200