wPrime 1024M
Wprime is one of the few well-known Pi calculators that uses more than one thread (both SuperPi and Hexus PiFast only use one thread). Haswell processors perform slightly better than their predecessors in this benchmark.
Hexus PiFast
Hexus PiFast is a single-threaded Pi-calculation software, which makes Hyper-Threading useless while running it. The Core i7-4770K is the winner due to its increased cache size.