It looks like it is more than 60% (cygwin, samsung x25). It does not matter whether you use backticks or a regular open to the date program, both are equally slow.

$ time perl -e 'do {open PROGRAM, "date +%s|" or die "can not open dat
+e $!";$time = <PROGRAM>;close PROGRAM} for 0 .. 1000'

real    0m14.733s
user    0m32.927s
sys     0m9.109s

$ time perl -e 'do { $time = `date +%s`} for 0 .. 1000'

real    0m14.717s
user    0m32.929s
sys     0m9.138s

$ time perl -e 'do { $time = time} for 0 .. 1000'

real    0m0.084s
user    0m0.061s
sys     0m0.046s
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