It takes about nineteen seconds for the matrix implementation in Ruby: ruby-1.9.3 043 > x = Time.new.to_i; y = 10000000.matrix_fib; Time.new.to_i - x

It takes about nineteen seconds for the matrix implementation in Ruby: ruby-1.9.3 043 > x = Time.new.to_i; y = 10000000.matrix_fib; Time.new.to_i - x => 19