C:\test>p1
$packed = pack 'V*', 1 .. 1e6;;
cmpthese -5, {
    unpack => q[ my @nums = unpack 'V*', $packed ],
    unvec  => q[ my @nums; push @nums, vec( $packed, $_, 32 ) for 1 .. 1e6 ],
};;
         Rate  unvec unpack
unvec  1.45/s     --   -45%
unpack 2.64/s    81%     --