By now, it's well documented how fast the new A9 processor is in the iPhone 6s. The benchmarks show a marked improvement over last year's iPhone 6, and it even compares nicely with the iPad Air 2.
The iPhone 6s benchmarks better than the entry-level 12" MacBook, and compares nicely with some the earlier generations of MacBook Airs. Needless to say, this device is quite something from a technical perspective. So much so, that I thought it would be fun to compare it with my MacBook Pro.
I decided to install iMovie on my Mac, and compare a 4K export between it and the iPhone 6s. By no means is this a scientific test, but the results paint a general picture that may surprise some people.