The Cardano triplet problem can be found here: https://projecteuler.net/problem=251
This project was started to test the efficiency of Swift. Objective-C results were about 15x faster than Swift on XCode 6 Beta4 and 7x faster on XCode 6 Beta 6. Swift still has a while to go but I'm sure Apple will be doing many optimizations along the way.
Check out the full blog post on Medium. https://medium.com/@glenyi/114692293795