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Knowledge base articles
Knowledge base articles provide concise, practical guidance for solving thermal, flow, multiphysics, space systems, and turbomachinery modeling challenges in Simcenter 3D.
Solver and performance
Procedures and recommendations for executing the thermal solver, managing restart workflows, and optimizing computational performance.
How to resolve Intel MPI performance issues on Windows with hybrid CPU architectures when running the thermal solver?
On machines with hybrid CPU architectures that combine Performance-cores (P-cores) and Efficiency-cores (E-cores), Intel MPI on Windows may experience degraded performance when running the thermal solver.

Knowledge base articles
Knowledge base articles provide concise, practical guidance for solving thermal, flow, multiphysics, space systems, and turbomachinery modeling challenges in Simcenter 3D.
- Model preparation
  Best practices for assembling and preparing simulation models.
- Thermal loads and constraints
  Guidelines for defining thermal loads, temperature constraints, and controller-driven conditions in a simulation.
- Thermal couplings
  Methods and best practices for defining, verifying, and troubleshooting thermal couplings in the model.
- Solver and performance
  Procedures and recommendations for executing the thermal solver, managing restart workflows, and optimizing computational performance.
  - How to run the thermal solver on clusters?
    This article explains two different methods on how to run the thermal solver on clusters for thermal-flow and multiphysics analyses.
  - How to resolve Intel MPI performance issues on Windows with hybrid CPU architectures when running the thermal solver?
    On machines with hybrid CPU architectures that combine Performance-cores (P-cores) and Efficiency-cores (E-cores), Intel MPI on Windows may experience degraded performance when running the thermal solver.
  - How to manage restarts and overcome challenges effectively?
    This article provides a comprehensive guide on managing restarts in thermal analysis. It lists changes that can and cannot be made while performing a restart, discusses common challenges, steps to ensure consistency in restart options, detailed instructions on selecting and configuring restart options, and best practices.
  - How to generate reduced thermal models in Simcenter 3D
    This article explains how to generate a reduced thermal model (RTM) in Simcenter 3D.
  - How to run a mapping solution in batch?
    This article describes the required command and input files for running a mapping solution in batch mode.
- Post-processing
  Techniques for reviewing results and interpreting thermal solver output.
- Troubleshooting
  Procedures for resolving solver errors, warnings, and convergence problems.
- Advanced thermal modeling
  Advanced methods for simulating complex thermal phenomena.
- Customization and plugins
  Guidance for developing plugins and custom tools to enhance thermal simulation workflows.
- Flow specific
  Flow specific knowledge base articles.
- Space systems specific
  Guidance for modeling spacecraft thermal environments, including multi-layer insulation (MLI), ablative materials, orbital heating, radiation modeling, and mission-specific boundary conditions.
- Turbomachinery specific
  Articles covering axisymmetric thermal modeling, bolt/nut interfaces, hybrid 2D–3D thermal mapping, thermal streams, voids, duct networks, and other turbomachinery-specific thermal workflows.
- FE model correlation and model update
  Model correlation and model update knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
- Legal notice
SST getting started
This getting started guide provides a comprehensive introduction to thermal modeling using Simcenter 3D Space Systems Thermal (SST).

How to resolve Intel MPI performance issues on Windows with hybrid CPU architectures when running the thermal solver?

On machines with hybrid CPU architectures that combine Performance-cores (P-cores) and Efficiency-cores (E-cores), Intel MPI on Windows may experience degraded performance when running the thermal solver.

P-cores are designed for high-performance tasks, with strong single-threaded performance. E-cores are optimized for background or lighter workloads, with lower power consumption. Although this design allows Windows to balance performance and efficiency, Intel MPI currently relies on the Windows OS scheduler to assign tasks, and the thermal solver tends to run exclusively on E-cores. Since E-cores are not suited for heavy MPI workloads, this results in significantly longer solve times.

Note:

Some Intel CPUs support Hyper‑Threading, which allows each physical core to present multiple logical processors to the operating system. In some cases, this can conflict with application threading—SMP/DMP—and impact parallel runs. If you encounter issues, disable Hyper‑Threading in the BIOS.

Verify core usage

To confirm if the thermal solver is running on E-cores only:

1. Launch your thermal solution.
2. Open the Task Manager → Performance tab.
3. Monitor CPU utilization to identify whether the workload is using P-cores or E-cores.
If calculations are only on E-cores, the run will be disproportionately slow.

Fixing performance issues

To improve performance, use one of the following methods:

Method 1: Adjusting Windows power options

Open the Control Panel.
Choose Hardware and Sound > Power Options.
Click Change plan settings.
Click Change advanced power settings.
Change the setting to High performance.
Apply and save changes.

This forces Windows to prioritize P-cores over E-cores when assigning MPI tasks.

Method 2: Using command line to set policies

You can configure scheduling directly via the command line by setting:

SCHEDPOLICY to 1, which allocates P-cores first.
HETEROPOLICY to 3, which prioritizes P-cores over E-cores.

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR HETEROPOLICY 3

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR SCHEDPOLICY 1

powercfg /SETACTIVE SCHEME_CURRENT

This method applies the settings directly to your active power plan.