I've built a system using a P180 and it's a very nice case to work with, but holy moly that's a lot of moolah. Most of the server systems I use at work are dual power supply, but that's because one is a backup for the other not because they are used in tandem. (Has to do with guaranteed uptime. The power supplies are hot swappable when/if one fails, too.) I thought that might be what they were doing here, too, but reading the P190 info at Antec
, I guess not. Those also appear to be the smaller form factor used in server machines. Those tend to be harder to find and more expensive than their normal-sized counterparts. They've made up for using smaller power supplies by adding larger case fans.