here are 2 pics taken from one of my rigs..
5x5850's in the left motherboard and 3x5850 in the right. 2x segotep GP1100G power supplies, each powering 4 cards:
What speeds are you getting out of that? 2.8 GH?
around 340Mhash / card, oc'ing them to 825/200.
running stable with uptimes 10-30 days on my other places. this one was rebooted today after an 8 days uptime.