My son has a Dell OptiPlex 790 DT which has a 250W power supply. He purchased a PNY GeForce GT 730 2GB DDR3 card to use with a new game that he purchased. The side shows a min of 300W. Will the 250W PS in his system work? I spoke with Dell and they said the biggest PSU for that system is 265W. Any assistance is appreciated. Thanks