Asrock H81 & Radeon 7990 incompatibility

[mrs]

Quick update: I opened a support case at Asrock, they supplied a beta BIOS update with 4G Decoding, but the problem remains the same:

- If the onboard graphics is disabled, I can boot with 3 GPUs
- If the onboard graphics is disabled, I cannot boot with 4 GPUs – blank screen, does not POST