That did the trick in combination with gen2 in BIOS for a PCI-E slot.

Managed to get it working on one rig but can't get it on other four. The four rigs after adding sixth card start booting without error but getting no output on any of the GPUs. All rigs are set to start mining on boot, so it must be that the process has stopped somewhere after booting as there is no debug code on the LED display. Going to try with SSH but need to punch some holes in switch first.

I'll keep 'playing' with this and write here if I find a solution.

Now I at least know there is a way. :-)

Thanks man!

Edit:

Thanks for the information and images of the mobo, tried changing to Gen2 earlier before but it doesn't seem to work always like it should ^ ( see text above ). Change to Gen2 only worked on one rig out of five and my mobo doesn't have "DMI Gen Speed" or similar. I'll keep playing with this and write back if I manage something.

Also just to let you know, I have the same problem as post #502 running with 5x 1060.