Some basic problems with butterfly: the calculating efficiency and the result

Hi there, here is a beginner become to use the butterfly tools and I meet some basic issues requesting for help.

I followed the tutorial from @Mostapha, and I saw the calculate speed in 21:41 is super fast. Though I set the number of cpus to 4,it takes me more than one and half hour to 145times.

This efficiency is a little low to me, and I wonder whether it’s normal, and how can I speed it up?

Another question is, though it has calculated for 145times, the result it shows seems too rough and not as useful as Mostapha’s 41 times calculation in his vedio:
this is the result in my computer,

and this is Mostapha’s.

Is there something wrong?

I don’t attach my files here for it’s just the same Mostapha used.
Thanks a lot for your kindness!

Hi, I wonder if anybody can give a hand?