So I bought a MSI Z170A Gaming M7 +6700K to mine with. Its all good until I want to use more than 3 graphics cards. Check BIOS and its ver 1.4 which is the release BIOS for this board. So I update to the latest version 7976v1K. I can get back into the BIOS and 4G encoding is there but it locks up when loading windows, the spinning dots just stop. Nothing is plugged into the board other than SATA drive and mouse and keyboard, 2x 4GB Vengeance ram at stock 2666. Windows version is latest 20H2. I have also tried the bios before this one 7976v1K and the first one to add 4G encoding which is 1.H and get exactly the same result. Also if I try to boot from USB Windows install the same thing happens. I'm at a loss. I could try every BIOS but there is a few on that page and of course there is always a risk flashing. Any ideas what could be the problem?