But set bios to default, boot with igpu (in bios is better to have auto for gpu, it's still reseting to whatever it want...)
Uninstall AMD drivers, use DDU
Reboot or power off (now you have to connect all gpus if you don't have), also enable 4g above in bios
Boot to windows again with igpu, look if you have all the gpus in manager (there will be only Basic Microsoft...) just the count matters (if not use DDU again check all the connectors)
Now install latest AMD drivers, after that apply ATI patcher.
Reboot (while turning off switch video cable to one of the GPU best is the one in mobo PCIE x16) to be sure go to bios check if 4g above is enabled and set primary gpu to auto again...
Now it should boot with all GPUs I've tested 5 max, it's like ritual to boot this but once you get it you can reboot how many times you want it will boot with all the gpus hopefully.
Hope I could help
I will keep this info just in case. I did not tried it yet since I managed to make 6 gpus work on SMOS and 5 GPUs on Windows 10.
1 rx 570 is powered and fans are spinning but Windows did not recognize it. Most likely a driver issue.
My configuration for SMOS: 4G enabled, PEG, PCI and DMI all set to Auto. When iGPU is Auto, HDMI cable is plugged into external GPU0. When iGPU is set to CPU graphics HDMI cable is plugged into onboard HDMI port. Both works. 6 cards hash normal. Nothing special yet since no bios mod and/or OC but 6 cards are green at least.
My configuration for Windows10 : Actually similar to what you said. Also PEG and PCI are on GEN1. iGPU is either CPU graphics or PCIE. 1 RX 470 and 4 RX 570 showed up and worked. 1 RX 570 is missing. A DDU and reinstalling driver from the scratch is likely to fix. I did not try .
Is applying ATI Patcher required? I though it was necessary for modded bios only not for stock bios.
My main problem was power setup. I have Dual Evga 850 G2 connected with an add2psu (as far as I know it is not original but a Chinese copy).
My first set up was 3 risers and 3 GPUs on each of main and slave PSU along with all the other stuff on main PSU as well. But only 4 of the GPUs turned on in this setup. 3 on the main and 1 of the slave PSU's.
Some says it should be ok while some says don't do it but power all the risers from same/main PSU and use slave PSUs only for PCIE gpu powering.
Well in my case the latter hold true mostly and partially. I am using one PCIE x16 (as x1) port directly on the mobo and 5 risers x1.
Each PSU has single molex channel with 4 molex connections and 3 sata channels with 4 sata connections each
Config-1
---------
Slave PSU--> 4GPUs and 1 SATA HDD
Main PSU--> 2 GPUs, 5 risers (2 individual sata-molex, 1 daisy chain of 2 sata-molex and 1 direct molex)
1 add2psu with direct molex (this molex channel powers one riser given as "1 direct molex" above)
Config-2
---------
Slave PSU--> 4GPUs, 1 SATA HDD and 1 riser on sata-molex
Main PSU--> 2 GPUs, 4 risers (3 individual sata-molex and 1 direct molex)
1 add2psu with direct molex (this molex channel powers one riser given as "1 direct molex" above)
As far as I know sata-molex conversion cables are used widely but also they are not advised by some folks because of GPU power requirement and SATA capacity.
Nothing less than a direct molex connection between PSU and a riser is not suggested.
In Config-1, I even used a SATA daisy chain to power 2 risers form same SATA channel with sata-molex conversions. In Config-2, I at least managed to break chain and used 3 separate SATA-molex conversions. 1 riser on sata-molex of slave PSU in Config-2 most likely will be direct molex since this channel is empty on slave now. I simply did not tried it yet.
Even after this, if I want to power as many risers as possible from main PSU, I am looking forward to at least 3 separate sata-molex conversions for 3 risers and 1 riser sharing a single molex channel with add2psu.
Is using sata-molex conversion cables a really bad idea? Are they dangerous? Rig is running at home.
These two setups worked for me for 5-6 cards depending on OS. If I could manage to power risers and GPUs by distrubuting on two PSUs (which did not get through yet) I may get 6 pin powered risers and 6 pin PCIE male/female conversion adapters to use empty 6 Pin PCIE power of VGA cables as I have several 6+(6+2) on the same VGA power cable where 6+2 goes to GPU and other 6 pin is empty.
I know this post is quite long but this is my first rig and I am struggling a lot to learn and share.
Thanks.