Re: Building a multi GPU system

I have also a question about that. I have a 5850 and a 5770 in a mobo Asus m2n-e sli. It has 2 pci-e slots so I can plug both cards but when I use the miner it only shows me the first one and in GPU-Z only the card that is in the primary slot has OPENCL. There is some way to use both to miner? At least I will have to use only 5850 but it would be great if I could use both.

Do you have a monitor plugged into it? If not, plug one in. Stupid quirk of the system requires it to have a monitor. If you lack a 2nd monitor you can search around on how to create a DVI->VGA null monitor adaptor (takes 3 75ohm resistors from radio shack to make it happen).

Ok thanks, do you know if dvi-vga adaptor that comes with the graphic card would do the same use?

No, you need to modify the one that comes with the PC. Follow this guide: http://www.overclock.net/folding-home-guides-tutorials/384733-30-second-dummy-plug.html

But based on other folks replies here, it seems like this is just going to expose the next problem you're going to have.