After reading through the users guide on optimization for the Intel Fortran compiler for Linux, I had a question. Is the optimization mainly for just compiling the code, or for actually speeding up the running of the code once compiled? I have been working on this, and I haven't really noticed any major difference in speed of running code with or without different optimizations. Am I doing something wrong? Is there a general technique that I should be using to get my code to run the fastest possible? Any help would be great. Thanks.