Mats Cronqvist wrote: > well, according to timer:tc/3; > > <<list_to_binary(As)/binary,list_to_binary(Bs)/binary>> > > is (marginally) faster than; > > list_to_binary([As,Bs]) Bizarre! I can't see how that is possible, except perhaps for lists of length =< 4. The first version needs to traverse the data twice to form the final binary. /Richard