Or to put it another way, the SPARC needs 800% more threads and a 24% higher clock to achieve only ~30% faster than the Intel. The POWER is somewhat, but not that much better, at 2.54 / 2.24.
The Intel chip, as benchmarked, is 2.1 GHz. The same design is available in 3.6 GHz, as of Q2 '12. We're comparing a top-clocked, circa 2013 SPARC to a 2012 Intel product running at 60% of the commercially available clock rate, and the SPARC comes up short.
I used this poor comparison because that was what was readily available in SPEC's published results for single-processor (SPECcpu) and parallel (SPECcpu_rate) benchmarks.
- SPARC T5, 128 threads @ 3.6GHz, 463 / 467 -> 1.01 / 0.946 result/thread/GHz
- Intel Xeon E5-2690, 16 threads @ 2.9GHz, 357 / 343 -> 7.69 / 7.39 result/thread/GHz
Or to put it another way, the SPARC needs 800% more threads and a 24% higher clock to achieve only ~30% faster than the Intel. The POWER is somewhat, but not that much better, at 2.54 / 2.24.