WRF 4DVAR v4.6.0 - Intel LLVM Compilers

[HathewayWill]

With the release of WRF v4.6.0, I have conducted a series of evaluations on the Weather Research and Forecasting Model (WRF) version 4.6.0, utilizing the Intel LLVM Compilers and associated libraries. The purpose of these tests was to assess the performance and compatibility of WRF v4.6.0 under the specified computational environment. Given the diverse nature of the issues encountered, I will be documenting each separately in subsequent communications, ensuring detailed discussions per topic. Attached to each of these communications, you will find a zip file containing all relevant logs.

System Specifications:

Operating System: Ubuntu 22.04.4
Memory: 64 GB DDR5 RAM
Processor: Intel Core i9-13900K
Storage: 1TB SSD

Compiler and Library Environment:

Intel LLVM Compilers, Version 2024.1.0:
ifx (Fortran compiler)
icx (C compiler)
icpx (DPC++/C++ compiler)
mpiifx, mpiicx, mpiicpx (Intel MPI wrappers for respective compilers)

Libraries:

HDF5 v1.14.4.2
PHDF5 v1.14.4.2
ZLIB v1.3.1
Libpng v1.6.39
Jasper v1.900.1
Pnetcdf v1.13.0
Netcdf-c v4.9.2
Netcdf-fortran v4.6.1

Preliminary Observations:The testing required additional compiler flags to address compatibility issues with Jasper and Libpng libraries, which appear to stem from advancements in compiler technology beyond the versions recommended by NCAR. These flags include:

-Wno-implicit-function-declaration
-Wno-incompatible-function-pointer-types
-Wno-unused-command-line-argument

Methodology:
Tests were conducted in both single-threaded and multi-threaded modes to evaluate performance scalability. The procedure involved:

Fresh installation of the specified packages and configuration in a new terminal.

Execution of the WRF model using the command ./compile with -j 1 for single-threaded and -j 16 (utilizing half of the available CPU threads) for multi-threaded scenarios.

Collection, archiving, and zipping of all log files and configurations post-testing.

Conclusion:
The tests conducted in the single-threaded configuration for WRF 4DVAR were sucessful and multi-threaded configurations using WRF 4DVAR with Intel LLVM compilers were not sucessful.

In the log files for the multi-threaded test there appears to be a module or two that are not linking or building properly. This causes a cascading error that proprogates through the installation.

WRF_4dvar_single_thread.zip
WRF_4dvar_multi_thread_fail.zip