The Census Bureau just released the 2014 Metro estimates. Austin was the fastest growing large city and third overall behind The Villages and Myrtle Beach:
http://kimt.com/2015/03/26/census-bureau-releases-2014-population-estimates/
From the article:
The Austin, Texas MSA ranked third fastest at a 3.2 percent population change between 2013 and 2014. The metro area, which includes the Texas capitol and Round Rock, the home of Dell Computers, added an estimated 57,500 people for a total estimated population of 1,943,299.