Hello Branimir, Tuesday, December 20, 2005, 9:48:48 PM, you wrote: BM> I've finally performed test on amd64 and result is a same as on intel. BM> KMP always wins. So KMP is best suited for non indexed strings BM> and I guess should be used in library as prefered search/replace method. BM> This test favors straightforward search. i'm 90% sure that straightforward method must be faster for one-time searches. your test may give better results with KMP algorithm just because you repeat the same search many times and it was automatically "run-time compiled" as described on the wiki page about KMP try to add {-# NOINLINE replace #-} to both programs and repeat comparision -- Best regards, Bulat mailto:bulatz@HotPOP.com