Execution time on Intel Core i7-7700K (the values given are subject to small variations) Num. of threads Time(sec) 1 4.78 2 2.75 3 1.59 4 1.44 6 1.06 8 0.84 10 0.90 16 0.82 32 0.84 From the data above it is clear that the performance no longer increases when the number of threads exceeds 8. This is because the CPU (Core i7-7700K) has 4 cores and each core can simultaneously run up to 2 threads (Intel Hyper-Threading Technology). Thus when the number of threads exceeds 8 the CPU is overcommitted.