Different executable behaviour when run from within Vtune Amplifier

[savtri]

Hi,

I would like to ask why the release configuration of my fortran program is much faster when run from within the Vtune Amplifier enviroment. Is this a memory management issue that I have to deal with?

[IanH]

Just to confirm - the exact same exe, with the exact same input, giving the exact same results, is faster when running under Vtune?

[SergeyKostrov]

Please provide technical details ( platform, compiler version / update, hardware configuration, what application does, etc ) to avoid any speculations about your problem. Also, it would be nice to see two sets of performance numbers to compare. Both sets need to be obtained with Release configurations of your application executed with and without VTune.

[Bernard]

Maybe part of your app's code executed only under VTune?

[SergeyKostrov]

>>...I would like to ask why the release configuration of my fortran program is much faster when run from within the Vtune Amplifier >>enviroment... It is possible to reproduce your problem and it happens when performance of application compiled for a Debug configuration ( slower ) is compared with a performance of the same application compiled for a Release configuration ( faster ) and executed with Vtune.

[Bernard]

That is true.You can for example clearly see it when in Debug configuration int 3 buffer(probably to trigger debugger breakpoint) is added to the function so during the execution there is overhead of buffer filing instruction in Release configuration no 0xcc filled buffer is used.

[savtri]

Hi everybody and thanks for your help.

I am currently running Visual Fortran Composer XE 2013 (Update 3) under Visual studio 2010 for Windows 7. The current Vtune version is is XE 2013 (Update 6). What I managed to figure out is that when I choose to run the Release version from within the Visual Studio environment (pressing F5) I get a slowed down behaviour. However when I run the Release version, either through Vtunes or by double clicking the executable I get what I am expecting.

This behaviour was not observed in any of the previous versions of the compiler.

[SergeyKostrov]

>>...What I managed to figure out is that when I choose to run the Release version from within the Visual Studio environment >>(pressing F5) I get a slowed down behaviour... - Did you change Intel Visual Fortran compiler command line options? - Please verify that all SPs for Visual Studio 2010 are installed. - If your application does some time consuming processing try to understand what part is working longer and simple logging with timing could reveal a root case of the problem ( let's assume in that case that there is possibly a problem in your application / but it still needs to be confirmed! ).