topic The newer compiler optimizes in Intel® Fortran Compiler

Horrible performance

Thomas_P_ — Tue, 10 Oct 2017 21:50:40 GMT

I have a program that I compile with the Fortran Intel Compiler 10. This program takes a long time to complete (it is measured in days). We decided to upgrade to Fortran Intel Compiler 17 - and now it takes 20% LONGER! Newer compiler, worse performance ???!?!?! There is absolutely no change to the code between the two compilers. When I open the solution with the new VS it converts the properties from 11 to 17 (I assume). Is there a known issue with this conversion that slows things down? The only properties that seem different are the Intel Processor Optimization selections (which used to be under Compilers but are now under Code - if my memory serves me right).

Any direction would be appreciated!

The newer compiler optimizes

Steve_Lionel — Wed, 11 Oct 2017 00:05:02 GMT

The newer compiler optimizes more. But try version 18 - I read that it is faster, If you still feel there is a problem, use the Intel Online Service Portal to report the problem and attach all sources necessary to reproduce the issue.

What compiler options are you

andrew_4619 — Wed, 11 Oct 2017 08:54:19 GMT

What compiler options are you using?

Are you comparing the Debug

jimdempseyatthecove — Wed, 11 Oct 2017 14:52:17 GMT

Are you comparing the Debug build runtimes or the Release build runtimes?

The default diagnostics for Debug build between V10 and V17 have included more runtime checks.

>>What compiler options are you using?

List command line options for both versions please.

And are the target platforms the same (both Win32 or x64)?

Jim Dempsey