https://community.intel.com/t5/Intel-Moderncode-for-Parallel/OpenMP-on-a-a-Intel-Core-2-Quad-processor-X5355/m-p/888788#M3667 We can't guess accurately what is in your application. For example, you may be using all the memory bandwidth at 2 threads. Tue, 13 May 2008 16:37:53 GMT TimP 2008-05-13T16:37:53Z https://community.intel.com/t5/Intel-Moderncode-for-Parallel/OpenMP-on-a-a-Intel-Core-2-Quad-processor-X5355/m-p/888787#M3666 I have a problem when i try parallelization with OpenMP on a a Intel Core 2 Quad (processor X5355)<BR /><BR />when i'm using a single proccessor the running time is : 48 minutes, but if i use four proccessors the running time is 23 minutes, but if use 5, 6,7,8 the running time is the same 21 MIN !!!... when i'm using 5 to 8 processors the paralelizacion time does not decreases ... <BR /><BR />what is the problem..?? <BR /> Tue, 13 May 2008 16:08:19 GMT https://community.intel.com/t5/Intel-Moderncode-for-Parallel/OpenMP-on-a-a-Intel-Core-2-Quad-processor-X5355/m-p/888787#M3666 verdolaga 2008-05-13T16:08:19Z https://community.intel.com/t5/Intel-Moderncode-for-Parallel/OpenMP-on-a-a-Intel-Core-2-Quad-processor-X5355/m-p/888788#M3667 We can't guess accurately what is in your application. For example, you may be using all the memory bandwidth at 2 threads. Tue, 13 May 2008 16:37:53 GMT https://community.intel.com/t5/Intel-Moderncode-for-Parallel/OpenMP-on-a-a-Intel-Core-2-Quad-processor-X5355/m-p/888788#M3667 TimP 2008-05-13T16:37:53Z