ANSYS Tutorial: Boosting your CPU Performance

Nowadays most of computers have multiple cores. As a result of the analysis models growing larger and larger each day, most ANSYS users will make sure that they are using the most of their CPU capacity. However, it is unfortunately quite common that the CPU usage is merely around 50%:

The solution is to utilize MPI (Message Passing Interface) software which distributes job to different cores parallel and thereafter increase the CPU performance!

When we install the ANSYS software, there is an alternative option to install this MPI. However, most of the users seem to ignore it… But do not worry; we don’t need to reinstall ANSYS from scratch. This little blog article explains how you can fix it right away.

The Procedure

We can find the installation file for MPI in the ANSYS installation directory, which is by default “C:\Program Files\ANSYS Inc\v130\prereq”. There are two MPI software in this directory and we should choose “HP-MPI-V2.0-060409.exe”. In the file “INSTALL_HP-MPI_README.mht”, located in the same directory, ANSYS provides a detailed description on how to install it.

However, to make it a little bit more obvious, we present some additional explanations:

1) Do not forget “run as administrator”;

2) Quotation marks should be included when caching your Windows password;

3) The same password as you login your Windows system:

4) System PATH environment variable looks like this:

After the installation is completed, start Mechanical and open “Solve Process Settings” under the “Tools” menu. In “Advance Settings” we can check Distribute Solution. Please note that a HPC license is needed to utilize more than two processors.

Rerun an analysis and verify that we now can provide a (almost) 100% CPU usage. But we have to notice, in FEM simulations, double CPS usage does not mean half simulation time as in CFD simulation. Usually we can expect 20~30% improvement.