Wrong execution timing due to crunching coefficients

[m-fila]

The CPU crunching calibration is usually reliable but sometimes gives unusual coefficients that result in too fast execution, e.g.

time,coefficients
88.692161046,"[3.852816083323439e-8, 3.9434714532976774e-11]"
88.796071137,"[3.853296514731578e-8, 3.942991021889538e-11]"
87.864658834,"[4.571606166398728e-8, 3.939937107527076e-11]"
89.485431836,"[3.852570476244465e-8, 3.943717060376651e-11]"
88.902169051,"[3.7569448576500895e-8, 3.9439752473304016e-11]"
90.147022516,"[3.755703643338787e-8, 3.945216461641704e-11]"
88.750739575,"[4.044163167177156e-8, 3.9428592327252103e-11]"
56.384039866,"[-1.012661948275485e-9, 7.897553731448687e-11]"
87.556725520,"[4.343310792242485e-8, 3.953655760491913e-11]"

The crunching mechanism should be improved to eliminate that behaviour