There are a ton of other threads that have solved the problem of which motherboards work with 6 or 6+ GPUs.

It's a misconception that there is a small subset of motherboards compatible with 6+ GPUs.

settings like TOLUD, and enable 4G decoding solve these problems.

Every 6/6+ PCIe slot board I've bought (MSI, ASUS, AsRock, and Biostar) needed BIOS config tweaking to fix the issue. They all work z170, z270, b250, b350.