MPI: Scatter Communication

Listed below are MPI_Scatter communication times for a variety of message sizes and processor partitions. The total communication time is listed in terms of CPU clock cycles, and the bandwidth is listed in megabytes per second.

4 processors

  CPU cycles per word for 256 word messages is 113.115234 (2.39 Mbytes/sec)
  CPU cycles per word for 512 word messages is 61.567383 (4.39 Mbytes/sec)
  CPU cycles per word for 1024 word messages is 37.243652 (7.25 Mbytes/sec)
  CPU cycles per word for 2048 word messages is 18.522949 (14.58 Mbytes/sec)
  CPU cycles per word for 4096 word messages is 13.463745 (20.05 Mbytes/sec)
  CPU cycles per word for 8192 word messages is 12.779846 (21.13 Mbytes/sec)
  CPU cycles per word for 16384 word messages is 11.428528 (23.63 Mbytes/sec)
  CPU cycles per word for 32768 word messages is 14.232101 (18.97 Mbytes/sec)
  CPU cycles per word for 65536 word messages is 18.083153 (14.93 Mbytes/sec)
  CPU cycles per word for 131072 word messages is 13.725357 (19.67 Mbytes/sec)
  CPU cycles per word for 262144 word messages is 12.565355 (21.49 Mbytes/sec)
  CPU cycles per word for 524288 word messages is 14.330978 (18.84 Mbytes/sec)
  CPU cycles per word for 1048576 word messages is 15.034769 (17.96 Mbytes/sec)
  CPU cycles per word for 2097152 word messages is 15.292357 (17.66 Mbytes/sec)
  CPU cycles per word for 4194304 word messages is 8.066438 (33.47 Mbytes/sec)

8 processors

  CPU cycles per word for 256 word messages is 143.701172 (1.88 Mbytes/sec)
  CPU cycles per word for 512 word messages is 80.947266 (3.34 Mbytes/sec)
  CPU cycles per word for 1024 word messages is 46.274414 (5.83 Mbytes/sec)
  CPU cycles per word for 2048 word messages is 28.278809 (9.55 Mbytes/sec)
  CPU cycles per word for 4096 word messages is 22.033081 (12.25 Mbytes/sec)
  CPU cycles per word for 8192 word messages is 19.536438 (13.82 Mbytes/sec)
  CPU cycles per word for 16384 word messages is 12.989960 (20.79 Mbytes/sec)
  CPU cycles per word for 32768 word messages is 22.690201 (11.90 Mbytes/sec)
  CPU cycles per word for 65536 word messages is 16.102524 (16.77 Mbytes/sec)
  CPU cycles per word for 131072 word messages is 21.026802 (12.84 Mbytes/sec)
  CPU cycles per word for 262144 word messages is 20.540657 (13.14 Mbytes/sec)
  CPU cycles per word for 524288 word messages is 13.918090 (19.40 Mbytes/sec)
  CPU cycles per word for 1048576 word messages is 14.046707 (19.22 Mbytes/sec)
  CPU cycles per word for 2097152 word messages is 16.404144 (16.46 Mbytes/sec)
  CPU cycles per word for 4194304 word messages is 9.125825 (29.59 Mbytes/sec)