TRM vs Icepak vs HyperLynx — the honest comparison.
TL;DR
- For board-level thermal + PDN — current density, copper heating, voltage drop, transient — TRM is faster to set up, an order of magnitude cheaper, and accurate enough for sign-off.
- For enclosure / chassis airflow CFD — fan curves, ducting, system-level convection — Icepak or SolidWorks Flow win, and TRM doesn’t pretend to compete.
- We sell and use TRM, and we’ll still tell you to buy Icepak when the problem is airflow. Pick the tool for the question.
The comparison
| Capability | TRM | Ansys Icepak | HyperLynx Thermal | SolidWorks Flow |
|---|---|---|---|---|
| Board-level copper/Cu heating | ✓ native | ✓ | ✓ | ~ simplified |
| Coupled PDN (IR-drop + thermal) | ✓ | — separate | ~ add-on | — |
| Setup time, first result | ~5 min | days | hours | days |
| Meshing skill required | none | significant | some | significant |
| Enclosure / fan CFD | — out of scope | ✓ best | — | ✓ best |
| Single-seat annual cost | $2.5–6k | $25–40k | $15–25k | $10–15k |
When TRM is the right tool
TRM solves the board as a 3D thermal + electrical network: it knows that copper resistance rises with temperature, that current crowds at necks, and that vias and planes move heat. That coupling is exactly what board-level questions need — “will this 60 A rail’s copper overheat?”, “what’s my IR-drop at 85 °C?”, “does this QFN stay under Tj_max in a transient?” You get an answer in minutes without becoming a meshing expert, and it correlates to bench measurement within a few °C in our experience.
When you genuinely need CFD
If the dominant unknown is air — fan selection, ducting, recirculation, system-level convection across multiple boards — you need a full computational-fluid-dynamics tool, and Icepak or SolidWorks Flow are the right buys. TRM models convection with heat-transfer coefficients, not a solved flow field; that’s the deliberate simplification that makes it fast, and the boundary where it stops. A common, sane setup is TRM for every board-level spin and Icepak for the one system-level airflow study.
The wrong question for a tool is “which is best?” The right one is “what physics am I actually solving?” Board copper → TRM. Chassis air → CFD.
Try it
TRM has a 14-day trial with sample boards, and we’ll run your board for you under PhySignoff if you’d rather not buy a seat yet.
References
- Adam Research, TRM documentation (Dr. J. Adam).
- Ansys Icepak product documentation.
- Siemens HyperLynx Thermal documentation.
- PhyCircuit, “A Study on EVAL-LTM4703-AZ with TRM,” 2025.