id 0 is always the main pci-express slot that should be indicated on your mobo manual.
its the upmost, full profile, x16 slot.
That being said. I think you might be having a xorg issue.
im not familiar with simplemining os but all my rigs are running on ubuntu 16.04 server.
Rarely i need to reconfigure xorg or I see similar problems.
Try to reconfigure your OS or burn a fresh one.