Hello,

System:

Intel G4400
MSI Z170a gaming M5 (updated BIOS to 1.D)
7x RX470 4GB
120GB SSD (UEFI)
Win10 Pro
8Gb Ram

I've been able to get 7 RX470 GPUs to work using MSI z170a gaming m5 however I ran into some issues.

I needed to first disable 4G, install only one card and load drivers. Then shutown, install all 7 GPUs, enable 4G and reset

However, with 4G enabled and PCIe set to GEN1, my system would not boot - would keep getting a black screen. To get around this, there's an option for Win8.1/10 optimization in the BIOS that I enabled. I have no idea what this actually does to the system. I haven't tried disabling this and rebooting to see if windows loads again or not now that the system recognized the cards. Does anyone here know what this BIOS config does? Has anyone been able to get 7 GPUs to work on this MB without enabling this option?

Also, what drivers are you running in general? I'm currently running the latest (17.5.2) and I have had issues before with older drivers causing the system to boot with a black screen.

Cheers