13. Fun and instructive programs

This is a grabbag of miscellaneous programs I have run in to which are fun and instructive, but don’t merit their own chapter.

13.1. Memory profiling with mbw

I benchmarked memory transfer using the program mbw (available in debian). This will give an idea of how fast programs run once they are fully loaded and don’t have much disk I/O. I ran:

$ mbw 1000

The output shows how long it took and what the transfer rate was. A powerful system is one where the transfer rate is large.

On some computers that I had sitting around in 2017 I got:

  • magicflute (my main machine):

markgalassi@magicflute:~$ mbw 1000 | grep AVG
AVG     Method: MEMCPY  Elapsed: 0.18005        MiB: 1000.00000 Copy: 5553.911 MiB/s
AVG     Method: DUMB    Elapsed: 0.11505        MiB: 1000.00000 Copy: 8691.858 MiB/s

  • papageno (my secondary machine in the other room):

markgalassi@papageno:~$ mbw 1000 | grep AVG
AVG     Method: MEMCPY  Elapsed: 0.36072        MiB: 1000.00000 Copy: 2772.267 MiB/s
AVG     Method: DUMB    Elapsed: 0.35681        MiB: 1000.00000 Copy: 2802.584 MiB/s
AVG     Method: MCBLOCK Elapsed: 0.26571        MiB: 1000.00000 Copy: 3763.492 MiB/s

  • HP stream laptop:

$ mbw 1000 | grep AVG
AVG     Method: MEMCPY  Elapsed: 0.36072        MiB: 1000.00000 Copy: 1325.256 MiB/s
AVG     Method: DUMB    Elapsed: 0.35681        MiB: 1000.00000 Copy: 1429.251 MiB/s
AVG     Method: MCBLOCK Elapsed: 0.26571        MiB: 1000.00000 Copy: 1967.454 MiB/s

  • ASUS C201 chromebook

$ mbw 1000 | grep AVG
AVG     Method: MEMCPY  Elapsed: 0.36072        MiB: 1000.00000 Copy: 1129.712 MiB/s
AVG     Method: DUMB    Elapsed: 0.35681        MiB: 1000.00000 Copy: 1390.579 MiB/s
AVG     Method: MCBLOCK Elapsed: 0.26571        MiB: 1000.00000 Copy: 1637.766 MiB/s