But your comparison isn't fair. You let the regex do way
much work than needed. There's no need to parse the entire
line, and only assign if there are exactly four fields - you
aren't doing that for the split
cases either. Also,
you only have one set of parens, yet you do four assignments.
Picking a simpler regex, and doing just one assignment
improves the speed with 50%!
$a=$1 if $myvar =~ /^[^,]+,([^,]+)/
Still not as fast as the split, but it shows that
proper Benchmarking is an art.