I've got to say, that sounds like a really good thing to try which I never thought of myself. If I am writing something heavy from scratch myself I would use this kind of technique (I always try to think of reducing allocation overhead etc even though I don't know if it really helps in perl but I always have c in the back of my mind) but it just didn't occur to try it this time as I was thinking along the lines of 'must start with new object each time to make sure its nice and clean'. I guess its dependent on the module code working properly though otherwise things like reused arrays of a smaller size second time round might still contain some old data? Regardless it will be an interesting test to run. Thanks