I just ran a series of experiments. In this case, I'm running on an old linux machine, and copying from a local disk to a nas-mounted directory.

Using File::Copy       : 129 seconds
system("cp blah blah") : 171 seconds
[download]

Now I tried a different approach: @files is a list of the 250 files:

my $cmd = "cd $olddirectory; tar -cvf - " . join(' ',@files) . " | gzi
+p -c -1 | (cd $newdirectory; gzip -c -d | tar -xvf -)";
system ($cmd);

Using gzip -9 : 64 seconds
Using gzip -1 : 57 seconds
Without gzips : 52 seconds
[download]

All times are for copying 250 small files amounting to 1084k. I also found that times scaled symmetrically with number of files.

For what its worth, rsync was copying at the rate of approximately 3 files per second, so the perl/tar method is much faster. (I tried perl in the first place because this directory contains 1.5 million files - rsync was taking more than a day just to collect file info...)

In this case, its apparently more necessary to minimize processing power versus network usage (otherwise gzip -9 would be faster).

As always, your mileage may vary...