awesome thank you very much. ive looked all over the place for the 1500w power supply from dell and cant get it what power supply could i get that would be a straight swapwe saw @AlienAndy drop a pair of gpu koolers in his R2: My rigs
@W8lifts says this about 980Ti SLI: 'the 980ti's in SLI seem to be just fine with a 850 watt PSU. Was a little surprised that the PSU could handle the load'. He did drop in a 1000w eventually. TX & Ti are rated at the same 250w tdp, so I'd say, try the 850 you have - if it shuts down - put it in your budget for something 1kW or better.
the part# for the 1500w / 1440w 12v max Delta is 0800GY (aka 800GY). Chat with Dell again using that part#.
Gaudio (ax1200i), Mark (EVGA 1600G2) & W8 (Rosewill & ax1200i) tried to install a new psu, but the system did not turn on; that either means user install error, a DOA chassis, or a finicky R2, I wish I knew. On the other hand, here --> Gman (ax1200i) W8 (EVGA 1000), SJ (EVGA 1300) & AlienAndy (ax1200) did pair new psu's either with the stock mthrbrd in R2 case, aftrmrkt mthrbrd in R2 case, or stock mthrbrd in a new case; in all three scenarios a psu worked with the original equipment, whereas other owners had an issue of unknown origin. I'm using the 1500w Delta, so I can't say which is best. Buy yours from a place that accepts a hassle-free return. Never re-use the stock case harness, only use the cables supplied in your new pouch. Wait for others input ...