Thanks for your replies. All to no avail I am afraid.
I tried the steps provided. Am now on 15.7.1 drivers as well. No matter what is connected to the hub, I still get no signal.
The desktop is still being rendered when i log in remotely, monitor is detected in both catalyst and windows, resolution and refresh are correct, displayport diagnostics in ccc show the monitor, but still no signal. I even tried hooking up my old samsung syncmaster to it and that works with adapter to dp but not through hub either.
Note: I was incorrect on the graphics card. It is XFX R9 270x. Also, I was able to get both displayport outs working simultaneously and both separately when going directly to the monitors, so they are not the issue.
Any more thoughts?