Excellent description. Just out of curiosity, I tried your second example on my idle system (linux, newer AMD quad). It used <2% cpu and showed 2-3 *microsecond* precision:

1279058169.099145
1279058169.599145
1279058170.099145
1279058170.599144
1279058171.099144
1279058171.599144
1279058172.099146
1279058172.599144
1279058173.099145
1279058173.599144
1279058174.099145
1279058174.599146
1279058175.099144
1279058175.599145
1279058176.099146
1279058176.599145
1279058177.099145
1279058177.599144

[download]

Then I started two fsck processes and 4 prime number searching threads which overtax all CPUs and FPUs. I got this:

1279057824.4011
1279057824.9012
1279057825.4012
1279057825.9011
1279057826.4012
1279057826.9012
1279057827.4012
1279057827.9012
1279057828.4011
1279057828.9011
1279057829.4012
1279057829.9011
1279057830.4012
1279057830.9012
1279057831.4030
1279057831.9012

[download]

Which still looks like 1-2 millisecond precision. This is of course much better than I need. I don't know how valid those tests are, though, so I'll have to read up on the linux kernel schedulers.

Any tips for code to do the actual writing? I'll probably use the autoflush=1 example posted in the thread.

In reply to Re^2: Any ideas for using perl as a simple pulse generator? by bfreemer
in thread Any ideas for using perl as a simple pulse generator? by bfreemer

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