>> To summarize: Benchmark comparisons only work if there is a sound >> mathematical foundation to reduce the noise. > > I am probably not qualified, but I am following the discussion for > some time. And I think there is a problem with the benchmarking > itself. If I understand correctly the nice tables show the same > code on the same machine so 40% difference or so is not ok. > > I had a quick look at ftbench.c and I have the impression that the > timer ist using by clock_gettime for every single iteration twice. > I had expected to do N iterations with a single clock_gettime before > and after N iterations. If the benchmarked code is short this will > accumulate errors that cannot be removed afterwards. But I may be > wrong...
Alexei? Werner