Here is the introduction of the benchmark FPU Mandel in Aida64
This benchmark measures the double precision (also known as 64-bit) floating-point performance through the computation of several frames of the popular "Mandelbrot" fractal. The code behind this benchmark method is written in Assembly, and it is extremely optimized for every popular AMD, Intel and VIA processor core variants by utilizing the appropriate x87, SSE2, AVX, AVX2, AVX-512, FMA, and FMA4 instruction set extension.
FPU Mandel test consumes 4 MB system memory per calculation thread, and it is HyperThreading, multi-processor (SMP) and multi-core (CMP) aware.
and Here is the result of the benchmark of my i7-6700 after lowering the voltage as much as 0.2V,
You can see it’s even higher than i7-3770k.
Aida64 can be obtained here, https://www.aida64.com/downloads