FWIW I was running 4x5870 and 1x5770 on an MSI 890FXA-GD70 without powered extenders and did not have any problems. I think 6 might be pushing it without extenders but from what I've read on these boards the answer seems to depend on type of motherboard and video card more than anything else.
awesome, thanks for the info. i'll give it a shot and if things start blowing up i'll take one out.
if you have problems booting via usb make sure MB firmware is up to date.
i've tried every bios revision up to and including the beta to no avail. apparently gigabyte has issues booting to that type of usb format. i popped the drive into a cheesy biostar to see if it would work and the rigs humming quite nicely. i think i may have to end up using linuxcoin for that board.
i love being the guy that not only bought a 990 board in anticipation of faildozer, but also bought one that can't use bamt