Here is my ethereum mining rig using 4U server case. Its currently mining in my rack in datacentre in Netherlands.
Claymore miner 174Mh/s using 850W. Bios modded for 29MH/s undervolt and overclocked memory.
Specs:
ASrock BTC v2 motherboard
Celeron 1820 CPU
2 x 4GB Crusial RAM
6 x XFX RX480 8GB
EVGA 1300 G2
6 x PCI-x usb powered risers (6-pin power plug not SATA! )
4U server case (customized to fit cards and moved middle fan wall to the front :) )