Hi Andreas, David, Thanks for your prompt reaction! You encouraged me to try out the Intel compiler suite. We installed icc & ifc, most of the time took fiddling with flexlm. For my C code I had to change the header sequence: -X -I$(IA32ROOT)/include -I/usr/X11/include -I/usr/include -I$(IA32ROOT)/substitute_headers The only flaw was that on linux rpc/xdr.h uses stdint.h, which I had to include manually into the code. For Fortran, the compiler gives quite a lot of warnings, I had one portability issue with a static array bound. C++ I didn't try yet. uname -a gives Linux neumann 2.2.18-SMP #1 SMP Sat Jan 20 07:41:17 GMT 2001 i686 unknown, the machine runs Suse 7.1. After that, I compiled a PDE simulation library and a fuel cell simulator containing OpenGL, mixed Fortran/C, lua extension language, and everything was remarkable smooth. No benchmarks yet, but the code appears to be correct (-O3). Best regards Juergen Juergen Fuhrmann Numerical Mathematics & Scientific Computing Weierstrass Institute for Applied Analysis and Stochastics Mohrenstr. 39 10117 Berlin fon:+49 30 20372560 fax:+49 30 2044975 http://www.wias-berlin.de/~fuhrmann mailto:fuhrmann@wias-berlin.de