I'm running nvOC - PXA.
It is now seeing and running 6 GPUs successfully.
This is what I did
- I upgraded the bios for mining (not sure if there was any point?
- Disabled onboard video
- Set video to use GPU
- enabling Mining Mode just caused to jump back to BIOS settings after Save and Exit, So I left it disabled
- I enabled Above 4G
- Disabled serial and parallel ports
- Othe PCI devices = Do Not Launch
- Windows features = Other OS
Hope this may help