The best pathscale fortran stream results for Opteron, at least for 1 core, about 1 year ago were obtained for -CG:use_prefetchnta -LNO:prefetch_ahead=4 -O3 -mp keys of compilation. May be there is some sense to play w/this parameters for Woodcrest also ? Yours Mikhail Kuzminsky Zelinsky Institute of Organic Chemistry Moscow