Brian Budge wrote: > Which command line arguments are you using? Mostly "-O3", but I've tried lots of combinations of different options and I haven't yet found the magic incantation. >Can you make use of sse2? Well, there is a C version that I wrote which uses gcc's vector extensions and SSE2... http://shootout.alioth.debian.org/gp4/benchmark.php?test=mandelbrot&lang=gcc&id=3 ...but right now I'm more interested in why normal complex<double>'s are so slow. Greg Buchholz