I picked some similar ones (hp c7000) up a couple of years back. You get a lot of cores for the money but the noise and power used...... Just the enclosure uses >500w here (6 * 2250w PSU's + fans etc)

Keep looking. Try for Gen 8 single servers..... at least you can run those individually @ ~250w each and if you can fool the bios on fans running you can mount proper heatsinks and run them quiet