As soon as Microsoft decided to ditch all the legacy support from IE (mshtml.dll) and fork it as a new browser (edgehtml.dll), everyone knew Edge's performance will skyrocket. And it sure did:
All measures collected on 64-bit browsers running 64-bit Windows 10 Technical Preview
System Info: HP Compaq 8100 Elite with Intel(R) Core(TM) i7 CPU 860 @ 2.80GHz (4 cores), 12GB RAM
In the above example, Edge blows away IE11 and passes Chrome/Firefox in two of the most popular synthetic benchmarks.
This performance boost will be available on all Windows 10 platforms such as Edge browser on Windows 10/Windows 10 Mobile (aka Windows Phone 10)/XBOX ONE. All the Windows Apps will also benefit from this directly.