vinnie_febs :
ZachyBeat :
vinnie_febs :
Right, but to say you will be fine with 500W PSU is a ludicrous thing to advise someone. His system will be pulling like ~470W and who wants to be that closed to their max wattage. This means the PSU will be running at near 100% load almost all the time.
R9 390 300w, 4790k 88w, other stuff about 50w. I'm not saying he's going to have growing room but I'm saying it would be fine. A 500w power supply can supply a maximum of 500w. It's not like the link you posted means the R9 390 is actually pulling 600w itself. If he has a Corsair CX 500w then yes I think it's a bad idea to be using it in a gaming rig demanding 450w. Keep in mind the only time he's going to be pulling that much power is when the CPU and GPU are both maxed out.
Well, then why not say that in your original comment to the OP. In the end it is absolutely not recommended as yourself have now pointed out. Of course it will run it, but it is not optimum to do so, this is all we are saying; including yourself now sir. All this been said, what is the argument here?
OP never stated he has a Corsair CX. A quality 500w PSU would work just fine with an Intel build. The only reason a 600w is recommended is because of higher TDP CPUs like the AMD FX series. Now, if Corsair's only 500w PSU is the CX/M model then yes his PSU is on the questionable side. With that in mind I would still recommend a higher tier PSU anyways and grabbing the R9 390 over the GTX 970.
If you, OP, are sticking with your current PSU then both GPUs are going to run equally well.