on windows 10 you can get 8 gpu to work, you MUST set every pcie option to gen 1 (there are 4 of them) and set secure boot to windows. you will want to install in EFI mode not bios mode. windows will NOT work with the integrated graphics, you must have a monitor hooked only to the gpu in the pcie slot closest to the cpu. windows needs to be installed with only 1 gpu plugged in. DDU, install patched/merged 17.x driver, reboot and let it setup the first gpu in device manage. plug the rest in and reboot, wait 15-30 minutes while it sets up every other gpu.
on linux i have 10 gpu's working on this board, and am going to be trying more soon (simple mining os supports this). This board will accept m2 adaptors in BOTH m2 slots, and also works with the 1x to 3 1x switch devices. warning on the switches: you must power them only with molex, and they can only be on the same power supply that your gpu and molex risers are on, consumer power supply deal only.. have not had any luck with gpu/6 pin riser on server power supplies. on linux you want to set every pcie option to gen 2 (there are 4 of them) and set secure boot to other os. linux will work with the integrated intel display on the motherboard. during bootup you may see some amd powerplay issues, you can ignore them. however if you get a kernel panic inspect all pcie and power connections.
- my one linux machine is doing 300mhs right now on 10 8gb cards
in either case, disable thunderbolt, disable usb 3.1, set the m2_1 slot to pcie. set the m2_2 slot to 2x. disable audio. enable 4g decoding. enable power on after power outage, don't overclock any cpu/ram stuff.
5 with no problem. 