Is that true that at each iteration if I assign 64*n (n is an integer) particles, there won't be idle workers waiting each other
No, that is not true. When you use parfor, the only way to avoid having cores idle waiting for other cores, is use a pool of size 1.
The question becomes how long they are going to wait. The answer to that is going to depend upon the variability in work loads.
When there are sufficient cores:
- the first 2/3 of the iterations are divided equally between the cores, large chunks
- the next 1/6 (I think it might have been) of the iterations are divided into smaller chunks and handed out to cores as the cores become available
- the remaining (1/6th?) iterations are handed out to cores individually as they become available.
It is possible in this scheme for cores to run out of individual iterations while one of the original large chunks is still executing.
