I'm running my rig on SMOS, 1080ti Gaming OC 11g Gigabyte, asrock h110 btc+ pro MB
As long i'm keep my rig at 8 GPU's it all fine, the moment I try to add 2-4 more it become extremly unstable.
Should I just keep it at 8 or there is a solution for 12 GPU ?
Its Probably a H110 intel chipset Limitation issue, Luckily you get the 8th GPU working well in fact it does only support 8 native PCI-e slots and the other PCI-e slots are for support on PCI-e extension chips.
https://bitcointalk.org/index.php?topic=1541084.5780Try to disable hw such as sounds, and USB but not guarantee to make it work, ensure also that you have enough PSU to handle the additional 2 GPUS