It comes with 3, 2+1 spare. It will beep at initial boot if any of the 3 are missing but it will run fine. Just press the alarm button and it silences it. Since my server is always running I would have to push the button once or twice every 6 months so not really that concerned. If all 3 fail ill just buy another case if I cant source the psus.I was recently look at these deals and I am quite curious, what are your plans for the PSU's considering they are quite hard to come by what are you going to do if/when one fails?