Guys, which MB did You test and recommend for 7gpu rigs? Beside MSI z97 gaming 5 that one is doin fine.
I think there are a lot of guys running 7 gpu are using a cheap ATX mobo with a PCIE 1x - 3x multiplier board. It's a little splitter card that plugs into a 1x slot and has a companion board with 3x pcie slots. You can get them for around $30 on ebay or Amazon.
6 gpu guys run asrock or biostar h81 mobos with 6 slots.
The Asrock H81 mother board is good for the 6 GPU. With that motherboard and 6X RX 480, you need only 1000W PSU.