According to John Poole, the founder of Primate Labs "Both models use Intel Haswell processors, so there are no major changes in processor technology. The 5-7% increase in performance is what I would expect from the 7% increase in processor frequency."
The result are : the new model is quite a bit faster that the 2011 and 2012 MacBook Air models. Single-core performance has improved by almost 45% since 2011 and almost 20% since 2012.
