I know that historically on Linux, Perl's I/O performance was not up to snuff. I don't remember the exact cause, but the situation was bad enough that with a default compile it could be faster to read data and split it into lines inside of Perl rather than have Perl do that splitting!

I believe that this has since been fixed.

Another vague memory tells me that enabling Unicode processing can add significant overhead to Perl's I/O.

And, of course, the default Perl 5.8 that shipped with Red Hat 9 was compiled with threads and significantly underperformed any version of Perl that you'd be likely to compile for yourself. People benchmarking that gave rise to a myth that Perl 5.8 was a lot slower than 5.6. Nope. If you compile with the same options, the speeds are basically equivalent. But the version of 5.8 shipped by Red Hat was slower than their version of 5.6. Here are [link|http://mathforum.org/epigone/modperl/clikingspimp/1068515972.2699.131.camel@localhost.localdomain|some benchmarks] that a friend of mine did.

Cheers,
Ben