I just placed a scythe ultra kaze behind the cards and one kind of angled over the top and that beast has been cooking averaging 1.8 ghash at about 780 watts with kill-a-watt meter and that is without turning off any power saving features yet because it was 430am and i was just happy it was working after two days of wanting to sell all my shet on ebay...lol
The MSI 890FXA-GD70 seems to not mind extenders, but only a couple and I've noticed you usually need slot 1 populated directly and then you can screw around from there. For example, a rig of mine that has been rock solid for over a week.
MSI 890FXA-GD 70
AMD sempron 145
slot 1 actually a 5870 on powered extender but no molex connected to it
slot 2 5870 directly connected to pcix16 slot
slot 3 5970 on powered extender with no power to it
slot 4 empty
slot 5 5870 directly on the board
when I say slot I mean pci-e x16 only
turned off as much crap in bios as i can think of to save power and it does 1.8 to 2 GH/s at about 750 watts average.
settings in cgminer as follows in my startminers.sh script:
./cgminer –o http://us.eclipsemc.com:8337
–u username –p password –I 9,9,9,9,9
gpu-fan 85 gpu-engine 950,950,820,820,950 gpu-memclock 410
Thing just beasts along with good temps. TIM and thermal pads replaced on 5970, 5870's just stock from that ben's outlet sale. man i wish ai bought more of those, they have all been great out of the box except one has no fan control. I got 8 and they all do 950.
on the asus board with the 4 5870's all in the slots. I have them at 950/160 and they have been fine overnight worst card temp right now is 74c lowest at 62.5c
They are also in an old case lying flat with sides still on. I'd probably be doing better with temps once I get the gumption to just rip it out and put the mobo on a wooden board with motherboard plate underneath of course and just line up two kazes behind the cards.
I also need to mess with the memclocks on that cgminer script, but have just been happy its been stable for a week so I don't dare.
I keep saying we need more sticky's/threads with just pure specs and settings for folks.