Ok guys I lost a lot of time and effort to make this work, so I will post this quick guide for others.
First of all it seems that the cpu-mobo is a good combo, nice price nice availability and more than enough cpu power for the task.
Here we go:
Step 1: install all hardware but just 1 GPU
Step 2: plug monitor on intel I-gpu, keyboard, mouse and lan
Step3: boot to bios and update bios via internet
Step 4. Install Windows 10
Step 5. Let windows auto-install GPU, then install 17.5.2 (tested and working) or any other amd driver you want to test. If you have modded GPU bios patch drivers now.
Step 6. Reboot into Bios. Advanced Settings --> System Agent (SA) configuration-->Above 4g Decoding = Enabled. DO NOT change anything ELSE. Do not set PCI-e to GEN1 or GEN2, it must be at AUTO!
Step 7. Save bios settings, DO NOT let the PC reboot , Shutdown as soon as screen goes black and fans spin down.
Step 8. install the rest of your GPU's (+5 for 6 GPU rig). Make sure all connections are good and secure.
Step 9. Boot to windows, give windows some time maybe 15 minutes will be enough. Windows will slowly recognize all GPU's. Check your Device Manager to see Progress.
Step 10. You are good to go!
Take note that if you want to boot into windows with less than 4 GPU you must first go into bios and set Above 4g Decoding = Disabled, then shutdown disconnect GPU's and boot into windows. To boot again with all GPU's go into bios and set Above 4g Decoding = Enabled, then shutdown connect all GPU's and boot into windows.
If you find this useful and want to say Cheers send me some of your first ETH or SIA: