I cannot beat the split. Here's some code inside code tags, and some output. Please do provide the output of your program if you want to make a point - relying on others to run the program reduces the chances people will actually spend time answering your questing. It's your loss! 
use Benchmark 'cmpthese';

our $buffer = "abcdef\x00ghik" x 10_000;
our %hash = map {(ord($_) => $_)} "a" .. "z";
our %array;
foreach my $ch ("a" .. "z") {
    $::array[ord $ch] = $ch;
}

cmpthese -1, {
    split    => 'my @a = split //, $::buffer',
    pack     => 'my @a = unpack "C*", $::buffer',
    pack_chr => 'my @a = map chr, unpack "C*", $::buffer',
    regexp   => 'my @a = $::buffer =~ /./g',
    hash     => 'my @a = map $::hash{$_}, unpack "C*", $::buffer',
    array    => 'my @a = map $::array[$_], unpack "C*", $::buffer',
};

__END__
           Rate     hash    array pack_chr   regexp    split     pack
hash     3.81/s       --     -35%     -39%     -39%     -56%     -87%
array    5.83/s      53%       --      -6%      -6%     -32%     -80%
pack_chr 6.19/s      63%       6%       --      -0%     -28%     -79%
regexp   6.19/s      63%       6%       0%       --     -28%     -79%
split    8.57/s     125%      47%      38%      38%       --     -71%
pack     29.6/s     678%     409%     378%     378%     246%       --

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In reply to Re: Convert string to array - performance challenge by JavaFan
in thread Convert string to array - performance challenge by rtillian

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