The questions below pertain to the CONVERGE 4.x.x installation process. For a more general list of FAQs pertaining to internal combustion, physical modeling, and other topics, go to https://convergecfd.com/support/faqs.
If you need help resolving an issue, please email [email protected] (US), [email protected] (EU), or [email protected] (India).
Why is CONVERGE running slowly?
If you observe poor performance, we recommend checking your latency as a first step. CONVERGE prints the node-to-node latency to the screen and to mpi_latency.log at the start of a simulation. You can also run the check_system utility to check the latency without starting a simulation. Example commands:
CONVERGE 4.0.0: mpirun -np 16 converge-ompi -u check_system
CONVERGE does not check out a license when you run this utility.
For high-speed interconnects like InfiniBand and Omni-Path, we have seen latencies ranging from about 2 µs to 25 µs. These numbers are highly dependent on system configuration. If a high-speed interconnect is available for your system and your latency is higher than you expect, it is possible that the MPI library is not configured to use the high-speed interconnect. Work with your IT team to check your MPI setup.
Do I have to use one of the MPI packages that was installed with the CONVERGE 4.x.x solver?
No. We include MPI packages in the CONVERGE 4.x.x installer only for convenience. If your IT team has set up their own MPI package in a supported version, we recommend using that instead. To do so on Linux, load the module for your organization's MPI environment immediately after loading the CONVERGE module. To do so on Windows, prepend the path to your organization's MPI environment files to the Path environment variable.
Can I copy the CONVERGE executable from the installation package to a different directory (on Linux) without running the CONVERGE_CFD Bundle script?
No. To install CONVERGE 4.x.x on Linux, you must run the CONVERGE_CFD Bundle script.
In CONVERGE 4.x.x, you do not need to copy or link the CONVERGE executable to your Case Directory when you run a simulation. Instead, you set up your environment so that the executable can be run from any directory.
I've already installed CONVERGE 4.x.y. How do I upgrade to CONVERGE 4.x.z?
Download the installation package for the new version and run the CONVERGE_CFD Bundle script (Linux) or the .exe installer (Windows). The directories for the new version (e.g., 4.0.0) are installed parallel to the directories for the old version (e.g., 4.0.1).