This is slightly faster on my computer: 
$s = time;
$out1 = chr(0) x 2e6;
substr($out1, $_ * 2, 1, substr($buf, $_, 1)) for 0..1e6;
print time() - $s, "\n";

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In reply to Re: Interleaving bytes in a string quickly by salva
in thread Interleaving bytes in a string quickly by BrowserUk

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