use Benchmark ();

our @data;
my $line = '1.000000     '
. '    100.273    121.54     98.169    121.58'
. '    100.273    121.54     98.169    121.58'
. '    100.273    121.54     98.169    121.58'
. '    100.273    121.54     98.169    121.58';

Benchmark::cmpthese(0, {
   split        => sub { @data = split(/\s+/, $line) },
   fixed_length => sub { @data = $line =~ /^.{8} {6}(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})$/ },
   var_length   => sub { @data = $line =~ /^.{8}\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)$/ },
});

__END__
                 Rate        split   var_length fixed_length
split         63116/s           --         -30%         -87%
var_length    90310/s          43%           --         -81%
fixed_length 482454/s         664%         434%           --