Machine issues & portability

On this page we provide links to compiler-specific information.

GNU Fortran compiler

The GNU Fortran compiler is our recommended open-source compiler for GEOS-Chem. Because gfortran is open-source, it can be used on a wide variety of platforms, including the [Amazon Web Services cloud computing platform]. GEOS-Chem is now compatible with gfortran 4.4.7 and higher. As of December 2018, the current version is gfortran 8.2.0.

Please see our GNU Fortran compiler wiki page for more information about the compilation options used by GEOS-Chem, as well as a list of known issues.

We are currently experimenting with the use of Linux containers (such as Singularity) in order to provide a consistent computational environment (i.e. with the same libraries and compiler verisons) that can be used across multiple platforms. For more information, please see: this tutorial by Jiawei Zhuang.

A note on performance: When GEOS-Chem is compiled with the GNU Fortran compiler, it runs slower than when compiled with the proprietary Intel Fortran compiler, especially when running on Intel CPUs. This is because GNU Fortran, as an open-source software product, lacks the ability to take advantage of some proprietary Intel CPU optimizations. If performance matters to you, and your institution has an Intel site license, then you might want to consider using the Intel Fortran Compiler instead.

--Bob Yantosca (talk) 19:34, 10 January 2019 (UTC)

Intel Fortran Compiler

The Intel Fortran Compiler (aka ifort) can currently be used to compile GEOS-Chem. However, this compiler is proprietary and requires that you (or your IT department) to purchase a site license, which can be expensive.

Please see our Intel Fortran Compiler wiki page for more information about the options used to compile GEOS-Chem, as well as a list of known issues.

--Bob Yantosca (talk) 22:16, 21 December 2018 (UTC)

PGI Compiler

NOTE: While GEOS-Chem can probably compile and run with the PGI compiler, we are no longer actively supporting it. We recommend that you use the open-source GNU Fortran Compiler instead.

Please see the Portland Group Int'l vendor website for PGI compiler documentation.

--Bob Yantosca (talk) 20:09, 5 December 2016 (UTC)

Compatibility issues added in v9-01-02

Please see this list of minor bugs that were corrected in order to get the GEOS-Chem code to compile with the PGI compiler.

--Bob Y. 10:04, 23 February 2012 (EST)

Error with ADJUSTL and ADJUSTR

For more information, please see this post on our PGI compiler wiki page.

--Bob Yantosca (talk) 19:24, 9 February 2016 (UTC)

Setting the stacksize

For more information, please see this post on our PGI compiler wiki page.

--Bob Yantosca (talk) 19:25, 9 February 2016 (UTC)