I found this useful if you're running Ubuntu 12.04 : - http://hardforum.com/archive/index.php/t-1695762.html
Saw your query on the official forum ..... have to admit, the barrier thing is a new one on me as well
Interesting. I've stuck with 10.10 because it seems to work fine and I have too many other things to do... good to see that it is considered to be OK.
I would probably keep to 10.10 but it will not run on my 3930K at all - doesn't seem to detect the HD during installation