Hello,
I have developed a large program using the 2013 edition of Intel's parallel studio (Professional Edition), with the Visual Fortran Compiler (integrated into Visual Studio 2012).
I recently downloaded the trial of the 2019 Parallel Studio (Cluster edition) with Visual Studio 2017, to see if the new version of the compiler leads to better performance with my CPU model (It is a Xeon E5-2697 v3).
In my benchmarks, I run the same exact code for the same level of optimization (O2), with all default options, apart from using Heap = 0.
To my surprise, the multi-threaded performance of my code when built with the new version of the compiler is abysmal, compared to the same exact code using the 2013 version of the compiler. I verified that the two compilers give similar performance for a single-thread execution of the code. A multi-threaded execution using 8 threads gives much faster execution when I use the 2013 edition of the compiler. Using 8 threads with the new edition of the compiler gives slower execution than the case with 1 thread! I am convinced that this is an issue of the windows-based version of the compiler, as the Linux-based version gives the expected performance enhancement when I use multiple threads.
In light of the above, I wanted to ask whether anyone has an idea what may be causing such slow-down when I use the newer version of the compiler. Could there be a default option/setting in the compiler or in Visual Studio 2017 which was not present in the old versions?
Thanks in advance for any suggestions and advice.