If it turns out to really be slow and you want to/have to stick with PHP, you could speed it up with the Strassen algorithm: http://en.wikipedia.org/wiki/Strass

If it turns out to really be slow and you want to/have to stick with PHP, you could speed it up with the Strassen algorithm: http://en.wikipedia.org/wiki/Strassen_algorithm http://en.wikipedia.org/wiki/Strassen_algorithm