Here are my specs:
Mobo - MSI Z77A-GD65
PSU - Rosewill Xtreme 850W (
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182072)
RAM - 4GB DDR3
CPU - Intel Celeron G1610 Ivy Bridge
GPU1: Gigabyte WF3 7950
GPU2: Gigabyte WF3 7950
GPU3: XFX Double D 7950
GPU4: Powercolor 7950
I am only using the first 3 GPU's due to the fact my 2nd Thermaltake 750W PSU hasn't arrived yet..
I managed to get all 3 GPU's working on the PCIE x16 slots. I then added a x1 to x16 UNPOWERED riser to the first x1 slot (the WF3), and left the other 2 GPUs on the first 2 x16 slots, and it turned the computer on for a split second and shutoff. Then I couldn't even press the power button to turn on anymore, I had to turn off the PSU, remove all the cards, then insert one card at a time for it to work.
The x1 to x16 unpowered riser I have works if I only use 2 cards (one WF3 and one XFX DD). If I add the 3rd WF3 card it shorts the PC I think.
When I use a POWERED x1 to x16 riser all 3 cards work. Does this mean that x1 slots can only work with powered risers?