BankHacker wrote: It is surprising that when the program is compiled with the static flag enabled, it runs very fast, doing 10 million calculations in only 0.4 seconds. Nevertheless, when it is compiled without the static flag (that is dynamic binary), the performance becomes very poor, consuming 40 seconds in doing it. This sure looks like an intel CPU problem. Here are my results on an AMD 4200 X2: -> ./dynamic-test-cpu-2 Reservado 0.1 Gb de memoria en 0.000 sec Escritura sobre 0.1 Gb de memoria en 0.680 sec 10 M de rand() en 0.140 sec (example.: 1574248880) 10 M de sqrt(i) en 0.180 sec (example.: 3162) 10 M de log(i) en 0.930 sec (example.: 16) 10 M de log10(i) en 0.980 sec (example.: 6) LINUX: 10 M de random() en 0.140 sec (example.: 1900205472) LINUX: 10 M de lrand48() en 0.120 sec (example.: 361466127)