sub Create {
    my ( $sourcePath, $destinationPath ) = @_;
    # ... create directories and stuff ...

    my $tq = Thread::Queue->new();

    for (1..5) {
        push @arrThreads, threads->create(
            sub {
                while (defined(my $item = $q->dequeue())) {
                    DoSomethingWithItem($item, $sourcePath, $destinati
+onPath);
                }
            }
        );
    }

    while (my ($k, $v) = each(%hashFileList)) {
        $tq->enqueue( $v );
    }
    $tq->end();
    foreach (@arrThreads) {
        my $num = $_->join;
    }
}
[download]

The major change here is that it's passing the files one item at a time to the threads. You're dividing them to n buckets and passing the whole bucket to the thread at creation time.

Apart from being nicer to look at, this one-at-a-time (supervisor-worker) approach should ensure that the threads will finish quicker since they're given equal amounts of work.