I am trying to set up my Asus P6T deluxe with a Radeon 4550 and a GTX 470. I want to use the ATI card for display and the Nvidia card for cuda stuff. I can't see anything when I connect the ATI card to my monitor.
The only place the Nvidia card fits is in the PCI-E x16 first slot. I tried fitting the ATI card in the second and third slot and it didn't help. I also tried changing the PCIE configuration in the BIOS from AUTO to 16,16,1 and that didn't help.
Another strange thing is that I can't see anything via DVI... I can only see when I connect to the monitor's VGA input. This is true for the current setup and also when I connected only the ATI card. I tried it with 2 different monitors and 2 different DVI cables.
You need to hunt down on your own time a patch that disables Nvidia's dirty little trick that disables ATI cards on start up. Just look around that is how people are running cuda and physx on hybrid systems.