How to get best performance of 8 core system using INTEL fortran

Please let me know how to set INTEL fortran compiler option to gain the best performance of 8 core system for开发者_开发知识库 IA32 and X64 bits. Actually I want to execute a fortran program and take the advantages of the all CPU time available in 8 core system. Now the program is only using 13 % of CPU time.

You can learn about autovectorization and guided auto-parallelization features of Intel FORTRAN in this tutorial: http://software.intel.com/sites/products/documentation/hpc/composerxe/en-us/start/win/tutorial_comp_for_win.pdf.

If you are doing linear algebra, solvers, FFTs, you might get best results if you map your problem into calls into the Intel Math Kernel Libraries: http://software.intel.com/en-us/articles/intel-mkl/ which are already multithreaded and vectorized and cache optimized.

If you are doing media / signal processing you might map your problem into calls into the Intel Performance Primitives library: http://software.intel.com/en-us/articles/intel-ipp/

Happy hacking!

In my specific application, a computational network model containing several loops running thoughout 20k iterations, each iteration accessing a number of nested if's, just by enabling /Q2 level optimization in the compiler was sufficient to reduce the computing time drastically, while keeping the CPU load around 15%. On a similar note, I have noticed rising the optimization setting to the last level (/Q3), did do what you were asking (running all CPUs at about full load), but the computing time have NOT been reduced at all. Therefore, if one has a small problem and several cases to test and processing capacity is the only bottleneck, it could be a good idea to open more than one Fortran solution and run those cases simultaneously.