No monitor display / output from 6 GPU system

[c6m0h3]

I built a system based on the MSI z87-G55 mobo and 6 Sapphire R9-270x. I am running Xubuntu 12.04. After a LOT of trouble I was able to get all 6 cards recognized by Linux. A quick "lspci | grep VGA" confirms that all are present. However I cannot get any output to the monitor from any of the 6 cards or the builtin VGA. I checked the Xorg.0.log file and there are no errors.

Thoughts anyone?