Using those settings above I was able to max out (2) Vegas for a couple hours. Added the third in with the same settings and now I'm getting about the same hashrate as before, 2 cards are running at about half speed. I'm ready to return these at this point..
When you restart your computer, always restart the cards, too.
See my post in the Cast thread:
https://bitcointalk.org/index.php?topic=2256917.msg24518280#msg24518280Also make sure you're explicitly running the
August blockchain drivers. Anything newer does not play well with Vega.