I should probably rephrase. I have all 6 GPUs on risers, the only time it does not post is when I have 2 of the x16 slots with the risers in them. I will double check and make sure they are all the same gen type. I had it on auto first but when I did, it wouldn't even boot past one card. I'm to the point I may just reset the MB bios via cmos and start fresh.
Use all 3 of the x16 slots, then begin populating the x1 slots beginning with the one closest to the CPU and moving away from it.
I did not try this but I did get it working.
Motherboard changes to get it to post:
DMI max gen 2
pciex16_1 link gen 2
pciex16_2 link gen 2
pcie spread spectrum clock disable
pcei speed gen 2
restore ac power on
hd audio controler disable
post delay time 0 sec
above 4g decoding enable
Current slots in use (check MB manual)
PCIEX1_1
PCIEX16_1
PCIEX1_2
PCIEX1_3
PCIEX1_4
PCIEX16_3
If I use the PCIEX16_2 slot claymore miner will not detect the GPU in that slot, skipping it posts and all 6 are registered.
Link to the stats
CC: 100
Mem: 1275
dcri: 20
Watt: 115 per card
802 watts from the wall