Asrock H81 & Radeon 7990 incompatibility
Interesting post confirming the 8 GPU limit is only related to the Windows AMD driver, this poster has 4x Radeon 7990 plus 2x NVIDIA cards = total 10 GPUs under Windows
4x 7990 is 8 GPUs. That's the maximum the AMD driver supports. Not sure what you're not understanding about that.
I was just sharing an interesting setup... no need to be so aggressive.
Quick update: I've been running 4x 7990s on the ASUS Z97-WS successfully. This board won't boot with 5x 7990.
This board won't boot with 5x 7990. oh jezuz pleaze...............
5x 7990 is 10 GPUs, and the AMD driver only supports 8. So even if it did boot, it wouldn't work.