Is this mobo compatible with this cpu?

Should work absolutely fine. I did notice the Black edition of that CPU (I hope that's what the BE stands for) is compatible with all bios revisions which means it will work off the bat without any updating. The specific model is not on the CPU support list but I know that it will work just fine, chances are you wont need to update the bios as you will probably get a new batch with one of the most recent revisions.

Edit: Just confirmed it will work off the bat (just plug in the CPU and it will work). Here is the link
http://www.cpu-upgrade.com/mb-ASRock/990FX_Extreme3.htm...