Having trouble adding additional graphics card

[silver fox]

I have tried to add a additional graphics card to my pc to help with gaming/crossfire. I have an integrated Radeon 8570D and adding a Radeon 6670 800M 2 GB DDR3 HDMI .
My motherboard is a ECS A55F2-M3, I have selected dual graphics in the EZ Bios.
When i boot up the pc neither port on the existing integrated graphic card or the new one are sending any signals to the monitor. While in the EZ Bios the mouse does not work even though it is lit.
Any help would be appreciated

[kalniel]

Does it work if you run straight off the 6670 in single GPU mode?

[Rawrz0r]

One problem I had were the drivers. I didn't have the drivers for my GPU so would only run on one screen unless in the bios I stated to use the IGP rather than auto or PEG.