actually, the core are the same power. I wasn't gonna go deep into the system for a blow to blow comparison and just giving people a ball park figure, but seems to me there are no choice but to go into detail. I am going to use Core Frequency, Bus Width and Threads to calculate computing power on each of the heads up.
Part 1 - E5-2692 2.7Ghz vs Opteron 6274 2.20GHz
Tianhe-2 32000 x E5-2692 spec
Core Frequency - 2.2GHz (2.7 Turbo)
Bus Width - 5GTs
Core : 12
Threads : 24 (Hyper-threaded)
Cache - 12-12-30
Intel Xeon E5-2692 v2 - CM8063501452600
Titan 18688 x Opteron 6274 spec
Core Frequency - 2.2Ghz (2.5 Ghz full core mode)
Bus Width - 6.4 GTs (2x3.2 GTs)
Core : 16
Threads : 16
Cache : 8/16-16-16
AMD Opteron 6274 - OS6274WKTGGGU / OS6274WKTGGGUS / OS6274WKTGGGUWOF
One look at the general spec. E5-2692 is clearly the winner. At 2.7 GHz, and 5 GT simultaneous transaction bus, and carry with 24 thread, the each threads can carry 5Gig transfer per second. Each core (2 threads each) could process 27 Gig (27 x 2^30) instruction per second. A single E5-2692 12 cores CPU would mean 324Gig (324 x 2^30) instruction per second.
While on the other hand Opteron 6274 at 2.5Ghz at 6.5GTs and 16 core with 1 thread each. A single Processor with 16 core would mean 260Gig instruction per second E5 beats Opteron 274 at about ( 1 : 1.2) in performance
Part 2 Xeon Phi 31S1P vs Nvidia K20X
Tianhe-2 48,000 Xeon Phi 31S1P
Core Frequency - 1.1Ghz
Memory per board 8GB
Max Memory Channel : 16
Core : 57
Titan - 18688 Nvidia K-20X
Core frequency - 2.6 Ghz
Memory Per board - 6GB
Max Memory Channel : 24
Core : 12
In this comparison, the Xeon Phi is a little ahead, While it have more (1/4 more to be exact) memory, it have 1/4 channel that balance out the memory for processing. However, at 57 cores @1.1Ghz, it would easily beats K-20X in term of computing power (57 cores @1.1 would mean 62.7GHz per processor for Xeon Phi, vs 31.2Ghz per processor for K-20X at a ratio of roughly 1:2 in performance
In this comparison Tianhe-2 have 32000 E5 and 48000 Xeon Phi on 18688 Opteron and 18688 K-20X (at about 1: 2 and 1:3 respectively) But the top speed for Titan is only half of that with Tianhe-. Which if we simply on computing power, Tianhe-2 could easily be 4 times faster than Titan.