Hello, I bought a Z77 extreme3 by ASROCK with 2 Radeon HD 7950s. I had to RMA one of my 7950s because it wasn't working when I put it in the first PCIE slot. I got the new GPU last night and I tried it and it works on my first PCIE slot.
Although both GPUs work now, there is a new problem that I wasn't aware of before. My device manager cannot detect the GPU from the 2nd PCIE slot. I even went to the bios and checked the system overview. I hovered the mouse on top of the picture of the 2nd PCIE slot and it said it was empty. It showed that my first PCIE slot was occupied though. Both GPU fans are running and are connected to the power supply. I even tried to swap the GPUs in different slots and I get same results.
I'm thinking about RMAing the Motherboard, but I wanted to get a 2nd opinion before I make such a commitment.
1 thing i forgot to mention, I took out the gpu from the PCIE slot1, and I connected my monitor to the gpu on PCIE slot2. Turns out, I get no signal on my monitor. When I take that SAME gpu and place it in my PCIE slot1, it works. So like I said, I'm positive that both of my GPUs work.
I updated BIOS.
The problem is not the bridge. The problem is with my motherboard not detecting any GPU on my PCIE slot 2 even when you have one seated in it that has spinning fans. This has nothing to do with crossfire.