30 Jan
2008
30 Jan
'08
3:45 p.m.
Hmm.. You lost me. Are you saying that the multi-threaded case with 4 threads has more than 4X communication as compared to the single threaded case?
Each thread calls Isend-Irecv 160,000 times. With 4 threads, there will be 640,000 calls. There is a barrier across the entire set. But there is no division by 4 in the time calculation. Rajeev