How to get maximum performance in GFlop / s Intel Xeon E5-2690?

Question

In this processor comparison, I managed to find the theoretical peak performance of the DP-371 GFlop / s for the Xeon E5-2690 (interestingly, it’s easier to find this information in Intel than the Intel support pages themselves). However, when I try to get this maximum performance, my output does not match:

• Frequency (in Turbo mode) for each core of Xeon E5-2690 = 3.8 GHz
• The processor can perform add and mul operations per cycle, so we get: 3.8 x 2 = 7.6
• Given that it supports AVX, it can perform 4 double operations per cycle: 7.6 x 4 = 30.4
• Finally, it has 8 cores, so we get: 8 x 30.4 = 243.2

Thus, the maximum performance in Gflop / s will be equal to 243.2 GFlop / s, and not 371 GFlop / s?

Answer 1

Turbo Mode not used to calculate Theoretical Peak Performance , you should consider something like:

CPU Speed ​​= 2.9 GHz

Core CPU = 8

CPU instruction per cycle = 8 (taking into account the AVX-256 → 256-bit unit, it can contain 8 values ​​of single precision) x 2 (add and mul operations, as you said) = 16

Putting it all together:

2.9x8x16 = 371 GFlops / s