the purpose is to take a string, split it and store it in memory in such a way that you can pass it around and not need to split it again when receiving it in some other part of the program.

Then nothing will be as fast as constructing an array of arrays and passing a reference to it around. It could not be so.

Reading between the lines, your main problem seems to be that yoo are inisting on copying the subarrays to local named scalars each time before using them, rather than just using them in-situ.

Ie. You are doing something like:

sub process {
    my( $AoA,  $thingToProcess ) = @_;
    my( $v1, $v2, $v3, $v4, $v5, $v6, $v7 ) = @{ $AoA->[ $thingToProce
+ss ] };
    
    my( $r1, $r2, $r3, $r4, $r5, $r6, $r7 ) = ( ... some calculation(s
+) involving $v1, $v2, $v3, $v4, $v5, $v6, $v7 ... );

    @{ $AoA->[ $thingToProcess ] } = ( $r1, $r2, $r3, $r4, $r5, $r6, $
+r7 );
    return;
}
[download]

When you could be doing:

sub process {
    my( $AoA,  $thingToProcess ) = @_;

    $AoA->[ $thingToProcess ][ 3 ] =  $AoA->[ $thingToProcess ][ 1 ] *
+ $AoA->[ $thingToProcess ][ 2 ];
    ...
    return;
}
[download]