Intel and Nvidia are marketing %
Numbers arent wrong by the way if you look at K20 its 80%+.
Fermi was tested by ORNL / Univ. Tennessee / Univ. Manchester it came up short of the 60-65% marketed @ 56%
AMD Tahiti on the other hand has been tested at 90%. Maybe I should have put an (*) next to AMD only one thats been tested outside of marketing.
(SP) 3.52 TFLOPS
(DP) 1.17 TFLOPS / 0.936 (80% marketed Efficiency)
Xeon Phi SE Line
(SP) 2.16 TFLOPS
(DP) 1.07 TFLOPS / 0.877 (82% marketed Efficiency)
(SP) 3.95 TFLOPS
(DP) 1.31 TFLOPS / 1.213 (93% marketed Efficiency)
(SP) 5.91 TFLOPS
(DP) 1.48 TFLOPS / 1.332 (90% Tahiti tested Efficiency)