dalethepcman :
Xeon PHI has it's benefits, but due to its low frequency (1ghz) it only shines in massively parallel x86 legacy applications. I see the E7v2 series chips being a much better all around solution as long as their frequency can stay in the 2ghz + area.
I think you got that backward.
The Phi shines in massively parallel supercomputing applications and typical "legacy" x86 code is nowhere near well-threaded enough to make remotely effective use of such massive parallelism. It delivers nearly twice the throughput per chip than a 3GHz E7v2 would, likely for a fraction of the cost at the expense of programming effort.
The E7v2 would shine in moderately threaded (more "legacy-like") x86 applications that cannot efficiently leverage Phi's massive parallelism and benefit more from E7's higher clock rate and IPC.
For HPC applications, both are needed since supercomputing applications often have a mix of both brute-force calculations that are a perfect fit for Phi and more linear computations that would benefit more from the E7v2, hence my bet that we will see systems combining both in the top-500 list next year.