dual r9 280x hdmi working but not mini displayport

[macguy54]

Is it an DP 1.2 SST or MST display? The latter can be troublesome in OS X, no sure if it needs some special fixes to work.

fixed the problem, it was the monitor causing all my issues, did a fresh install with the new monitor as outlined in the main skylake guide and everything works, audio, ethernet.

is there any benefit to changing the framebuffer to the one u suggested? currently it lists 7870.
btw thank you for the responses.