[Newbies] Binary file I/O performance problems

[Herbert König]

Hello David,

DF> focuses on just reading a small (for us) 123 Mb data file on disk. The
DF> program takes about 166 seconds to run compared to 1.2 seconds for an
DF> equivalent C version (140x faster than Squeak version).

number crunching and raw speed are not the points where Smalltalk
excels.

0 tinyBenchmarks gives '322824716 bytecodes/sec; 8945704 sends/sec'
which is about 9 million sends on my 1.8 GHz Pentium M.

In the browser when you will switch from Source to Byte codes in the
lowest pane (rightmost button) you will see the many sends in your
code. Some of these code fragments (e.g. the arithmetic) would be a
lot faster in any compiling language.

With this you can estimate the performance you can expect.

If it would only take one send per byte read from the file my Computer
would take about 10 seconds for 100MB.

That's the price for dynamically looking up the receiver's class for
every send.

So I guess this application is better left for other languages.


Cheers,


Herbert                            mailto:herbertkoenig at gmx.net