Nice! I'm interested to know if you can manage to get all 6 running from one mobo. If you can close off the case (with slots for the PCIe wiring) and arrange the extra PSUs a bit better (so everything is blowing hot air in the same direction), you could pretty easily get all air flowing from front to rear and make a little home made setup to vent all the hot air away. Did you do anything special such that all those cards aren't drawing power from the PCIe bus?
In the end I gave in after going through many potential fixes from XFX - probably something limiting it on the SC440 MB. I've now changed to using 2xGA-E350N-USB3B each with 8GB RAM/8GB USB Flash/PCIe Switch/3xHD5870/650W PSU (aircon blows over the cards so they are kept quite cool).
http://dnshistory.org/dump/IMAG0087sc.jpgChrisB.
