From left to right they are labeled as PCIE 6, 5, 4, 3, 2, 1, BUT it's not the same order as it is in your miner.
In softwares like MSI Afterburner or EVGA Precision the order is (from left to right) 6 5 4 3 1 2 so the x16 slot is the first.
But in (nvidia) miner softwares the -d order is completely different. For AMD I have no idea.
Ah i see.
I am going to start moving rigs over to ETH later today and i already started about how to get everything to work.
Right now i am only running a testrig on Ubuntu mining with etherminer. I have one gpu mounted in port 0 (in the picture) and it is named gpuminer0 in etherminer.
I guess i will sort it out on the way.