# Cycles vs spawns

Dear @cesc, I read your reply under the topic of How to utilize multi-core/thread to speed up the simulation? - #2 by cesc. And I have a question: when I click on the grey rectangle in column"Spawn", if I enter 5, can I select the number of cycles as 1? In other words, I want to get a result with relative error, if I don’t set Spawn, I usually need to select the number of cycles as 5(≥5). Whether the above two cases have the same result？

Yes

A simulation that runs, without using spawn, for 5 cycles and n primaries (total number of simulated primaries N = 5n ) and a simulations that spawns over 5 cores each using 1 cycle with n primaries (total number of simulated primaries N = 5n ), have the same statistical significance. The numerical result might be slightly different (as different random number sequences would be used) but in lim_{n\rightarrow \infty} then they will be the same.

Have a look at this lecture for more details.

Thanks for taking time to reply my question!