Some quick benchmarking using the Intel MKL double precision Linpack benchmark shows Haswell to have the potential to be a stellar performer for floating point heavy code.
Will your motherboard work with Intel Xeon Phi?
Want to try your hand at programming the Intel Xeon Phi? Think a card will work in your existing system? …probably not!
Intel Xeon Phi – Introduction (Prelude)
What’s in a name … the Intel Xeon *Phi* ?