which one is faster
 

Hi
I am doing a project in Compaq fortran.
Is it better to build an exe file and run it instead of copiling the code for having faster performance? of there is no difference between them?
Please give me a scientifically-approved response

your question is not clear to me ... what do you mean for "instead of copiling the code for having faster performance"
Compaq Fortran is a very old compiler (migrated to Intel), better performances can be now obtained by modern compiler.
However, for having better performance is better to create the exe file, using all the optimization procedures (O5, loop unroll, etc.) after you are sure that no bugs are (presumibly) present. The problem is that your exe file is optimized for old architectures and can run slowly on the modern multi-core

Thank you dear friend.
I mean for my code, I can build an exe file and run it on any other PC that fortran may not be installed. and also I can go to RUN menu and click on run.
For one case, in which case the speed of running the code is faster without any attention to optimizations settings. for the same code on the same PC.

Apparently you work under Windows as you have an exe file. First migrate under Linux (whatever the distribution) Linux has a better managment of RAM memory than Windows. Then as Filippo suggested it Intel compiler is very efficient. I have compiled the same source code under force 2 compiler/windows and Intel compiler/Linux and I obtained 30% of decrease of the CPU time with Intel/Linux.