It is working so it does work. 
Power Draw R7 250 Optiplex 3010 MT I have a Dell Optiplex 3010 MT with the following specs: 16gb DDR3 1600Mhz i5 3450 The OEM PSU (275w)   Can a run a R7 250 2gb overclocked? I saw that the R7 250 OEM has a TDP of 65w. Since the PCIe should supply 75w it should work. However, the overclock has a max power limit of 20%. 65+20% is 78w. Does the PCIe have enough power for 78w or do I need to lower my overclock.
Power Draw R7 250 Optiplex 3010 MT