More than 3 r9 2xx GPU's in Ubuntu

[artiface]

Im trying to use 6 x r9 270x PCI card with this motherboard
http://www.amazon.com/Gigabyte-GA-F2A85X-UP4-Chipset-Motherboard-Display/dp/B00A6O7ZGW/ref=sr_1_3?ie=UTF8&qid=1386014082&sr=8-3&keywords=Gigabyte+GA-F2A85X-UP4

I have powered risers and a 1500 watt PSU and plenty of PCI-E power connectors.  

I had to use the AMD Catalyst™ 13.11 Beta V9.4 Driver for Linux

It installed fine

I did

sudo aticonfig --adapter=all --initial
sudo reboot

and then

sudo aticonfig --adapter=all --odgt

but it only shows 3 of the GPUs

Is there anything special I have to do with the driver to get it to recognize more than 3?