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Aethermor: Independent Technical Review

Date: 2026-03-11 (original) · 2026-03-30 (current revision) Scope: Full codebase, physics models, analysis tools, tests, documentation, and claims audit.


Executive Summary

Aethermor is a thermodynamic computing research toolkit that integrates Landauer-aware energy modeling, 3D Fourier thermal simulation, heterogeneous chip floorplanning, cooling stack design, technology roadmap projection, and inverse thermal design into a single exploratory workflow.

It is designed to answer questions that are usually spread across separate tools and manual sweep campaigns:

  • "Given my 50 W power budget, 7 nm process, and liquid cooling, how should I distribute compute across CPU, GPU, cache, and I/O to maximise throughput without exceeding 450 °C?"
  • "Where is thermal budget wasted on my heterogeneous SoC?"
  • "At what frequency does adiabatic logic overtake CMOS on SiC?"
  • "How does my cooling architecture's diminishing-returns floor change between silicon and diamond?"

These are questions hardware researchers currently answer through manual COMSOL sweeps, HotSpot configurations, or custom scripts. Aethermor integrates them into a single API and interactive dashboard.

Test suite: 308 tests passing, 1 skipped (dashboard requires optional dash). Energy conservation: 0.00 % error in 3D Fourier solver (tolerance: 5 %).


Section 1: What Makes Aethermor Different

1.1 Inverse Thermal Design

Most thermal tools solve the forward problem: given a design, compute the temperature. Aethermor solves the inverse problem: given constraints, find the best design.

Capability What it answers Method
find_max_density() Max gate density a substrate + cooling can sustain 3D simulation binary search
find_min_cooling() Minimum h_conv for a target density Combined conduction + convection 1D model
material_ranking() Which substrate allows the highest compute density Multi-material sweep
cooling_sweep() How temperature responds to cooling changes Sweep with conduction floor detection
paradigm_density_comparison() CMOS vs adiabatic: how much more compute? Head-to-head 3D search
thermal_headroom_map() Per-block thermal budget utilisation on a heterogeneous SoC Analytical per-element model
optimize_power_distribution() Optimal gate density distribution under power + thermal limits Constrained allocation with thermal/power binding detection
full_design_exploration() One-call comprehensive design space analysis Combines all above

This integrated inverse-design workflow is Aethermor's core differentiator. Individual thermal tools (HotSpot, COMSOL, custom scripts) can be configured to perform some of these tasks, but Aethermor packages them into a single, validated, interactive environment. HotSpot's HotFloorplan offers optimization-oriented thermal analysis; Aethermor adds Landauer-aware energy models, multi-paradigm comparison, cooling stack modeling, and extensible registries on top of the thermal core.

The value is workflow compression: what normally requires configuring multiple tools and writing glue code becomes a single function call or dashboard interaction.

1.2 Physics Foundation

All models use SI units with calibrated parameters:

  • 21 substrate materials: Si, SiO₂, GaAs, Diamond, Graphene, Cu, InP, SiC, GaN, Al, W, Mo, AlN, Al₂O₃, BeO, Sapphire, Ge, SAC305, FR-4, thermal grease, AlSiC
  • 4 computing paradigms: CMOS, adiabatic, reversible, Landauer limit
  • Fourier 3D thermal solver: Verified at 0.00 % energy conservation error
  • Combined conduction + convection 1D model: Captures both the convective cooling sensitivity AND the irreducible conduction floor set by substrate thermal conductivity. This is physically correct — it's why "better fans don't help" beyond a certain point.
  • Cooling stack: Multi-layer thermal path (TIM, heatsink, fan, liquid) with 11 pre-built layers and 6 factory configurations
  • Chip floorplan: Heterogeneous SoC model with per-block paradigm, activity, tech node, and density — factory methods for modern SoC and hybrid CMOS/adiabatic
  • Extensible registries: Engineers can register custom materials, computing paradigms, and cooling layers at runtime — all flow through the full pipeline

1.3 Technology Roadmap

Projects energy, Landauer gap, paradigm crossover, and thermal wall across 10 technology nodes (130 nm → 1.4 nm). Answers: "When does adiabatic logic become necessary? At what node does silicon hit its thermal wall?"

1.4 Key Physics Insights Aethermor Enables

  1. Cooling diminishing returns: At h_conv = 50,000, going to 100,000 gains almost nothing — the conduction floor dominates. This is invisible to tools that model only convection.

  2. Thermal headroom waste: On a typical SoC, I/O and cache blocks use < 5 % of their thermal budget while the CPU is at the limit. The optimizer shows ~2× throughput improvement by redistributing compute density.

  3. Material selection: Diamond sustains 39× higher compute density than GaAs at equal cooling — but only matters when you're thermally limited. The tool quantifies exactly when that is.

  4. Paradigm crossover: At 1 GHz on silicon, adiabatic logic allows 191× higher density than CMOS. The crossover frequency where CMOS becomes competitive is technology-node dependent — the roadmap finds it automatically.


Section 2: Code Quality & Engineering

2.1 Test Suite

308 tests across unit, integration, regression, robustness, and performance layers:

Module Tests Status
Physics constants & materials 13
Energy models (CMOS, adiabatic, reversible) 16
Thermal transport (3D Fourier) 16
Cooling stack 26
Chip floorplan 23
Tech roadmap 15
Thermal optimizer (incl. headroom, redistribution) 51
Landauer analysis, design space, regime maps 16
Extensible registries (material, paradigm, cooling) 43
Integration & regression 38
Benchmarks, statistics & publication gates 18
Numerical robustness (edge cases, bad inputs) 31
Performance & dashboard 3 2 pass, 1 skipped (dash)

2.2 Validation Suite — 133 Physics Checks

Beyond unit tests, Aethermor includes a dedicated validation suite that cross-checks every physics model against published reference data, analytical solutions, conservation laws, and internal self-consistency.

python -m aethermor.validation.validate_all    # 133 checks, ~13 seconds
Validation Area Checks Reference Source
Fundamental constants 6 CODATA 2018 / NIST
Landauer limit 5 Landauer (1961)
Material properties 18 CRC Handbook 97th ed.
CMOS energy model 13 ITRS 2013 / IRDS 2022
Fourier solver vs analytical 5 Carslaw & Jaeger
Analytical 1D model 7 Manual R-model cross-check
Max density reciprocity 5 3D ↔ analytical agreement
Min cooling inverse 4 Constraint round-trip
Optimizer constraints 9 Budget/thermal/binding
Headroom map physics 11 T + headroom = T_limit
Cooling stack resistance 4 Incropera & DeWitt
Tech roadmap monotonicity 28 10 nodes, gap > 1
Dimensional analysis 4 Unit consistency
Full exploration completeness 11 Response schema
Reproducibility 3 Deterministic outputs

See VALIDATION.md for full methodology, reference citations, and interpretation guide.

2.3 Code Structure

aethermor/physics/          # SI-unit models
  constants.py    # k_B, Planck, Boltzmann, landauer_limit()
  materials.py    # 21 substrates + extensible registry with validation
  energy_models.py  # 4 paradigms + extensible registry with protocol checking
  thermal.py      # FourierThermalTransport (3D solver)
  cooling.py      # CoolingStack + extensible layer registry
  chip_floorplan.py  # ChipFloorplan, FunctionalBlock

aethermor/analysis/         # Research tools
  thermal_optimizer.py  # Inverse design (8 capabilities)
  design_space.py       # Pareto sweeps
  landauer_gap.py       # Gap analysis
  regime_map.py         # Operating regime classification
  thermal_map.py        # Temperature field analysis
  tech_roadmap.py       # Node projection (130nm to 1.4nm)

aethermor/simulation/       # Monte Carlo / evolutionary simulation engine
examples/         # 7 runnable research scripts
experiments/      # Reproducibility scripts (ablations, scaling, fault sweeps)
tests/            # 308 tests (pytest)
aethermor/validation/       # 133 physics cross-checks (validate_all.py)

2.4 Reproducibility

  • Seeded RNG everywhere (np.random.seed, random.seed, AETHERMOR_SEED)
  • SHA-256 manifest tracks script versions
  • CI pipeline (GitHub Actions) runs tests and dependency audit
  • All examples produce deterministic output

2.5 OSS Governance

  • Apache 2.0 license, CONTRIBUTING.md, CODE_OF_CONDUCT.md, SECURITY.md
  • CITATION.cff, CHANGELOG.md, RELEASE_NOTES
  • pyproject.toml with setuptools.build_meta
  • Install: pip install -e . (core: numpy, pandas, scipy, matplotlib)

Section 3: Honest Limitations

3.1 Legacy Benchmarks

The four original benchmark scripts compare "having an active controller" against "having no controller" on an abstract grid-based lattice. The large effect sizes (Cohen's d = 18-41) confirm the mechanisms work as intended.

These benchmarks remain in the codebase as validation that the mechanism implementations are correct. They are clearly documented as such.

3.2 3D Sim Convergence

The 3D Fourier solver uses explicit time-stepping. For meaningful steady-state temperatures, the simulation must run enough steps to traverse several thermal time constants. Coarse grids with large elements may need thousands of steps. The analytical models (used in the optimizer and headroom map) give exact steady-state results without convergence concerns.

3.3 No Custom Silicon Measurement

All results are from physics-based models validated against published hardware measurements (JEDEC θ_jc, IR thermal imaging, HotSpot benchmarks), not proprietary internal measurements on custom test chips. The energy models use published device parameters (ITRS/IRDS-calibrated V_dd and C_load scaling), but real chips have layout-dependent parasitic effects, non-uniform heat spreading, and manufacturing variation not fully captured here.

3.4 Gate-Level Abstraction

The models operate at gate-level energy (E_switch x density x activity x freq), not at circuit-level or transistor-level detail. This is appropriate for architecture-level thermal budgeting but not for detailed circuit design.


Section 4: Competitive Position

Capability Aethermor HotSpot COMSOL Custom scripts
Forward thermal simulation 3D Fourier Compact + grid FEM varies
Inverse design (find optimal) 8 integrated tools HotFloorplan (layout opt.) Scripted sweeps Manual
Landauer gap tracking per-paradigm No No No
Multi-material comparison 9 + custom Limited Yes No
Adiabatic/reversible paradigms 4 + custom No No No
Cooling stack modeling multi-layer Package model Yes No
Technology roadmap 130nm to 1.4nm No No No
Heterogeneous SoC floorplan Yes Yes Yes No
Thermal headroom map per-block Partial (temps) Partial No
Power redistribution optimizer Yes No No No
Custom material/paradigm registry Yes No No No
Interactive explorer UI 6 tabs No No No
Open source Apache 2.0 BSD No ($25k+/yr) varies

Verdict

Dimension Grade Notes
Code quality A Clean, 308 tests passing, well-structured packages
Physics validation A+ 133 cross-checks against CODATA, CRC Handbook, ITRS/IRDS, analytical solutions. 20 literature cross-checks (Incropera, CODATA, CRC). 33 real-world chip validations (A100, M1, EPYC, i9-13900K). 18 experimental measurement checks (JEDEC θ_jc, IR thermal imaging, HotSpot benchmark).
Statistical infrastructure A- Rigorous paired ablations, Holm correction, bootstrap CIs
Reproducibility A Seeded, manifested, CI-verified, deterministic validation suite
Physics foundation A SI-unit models, 21 materials, 4 paradigms, 0.00% energy conservation
Inverse design capability A 8 tools: max density, min cooling, headroom map, power redistribution, material ranking, paradigm comparison, cooling sweep, full exploration
Claims accuracy A- All current claims backed by physics models. Legacy benchmarks honestly documented as mechanism validation.
Documentation A README, LIMITATIONS, HONEST_REVIEW, VALIDATION.md, 7 examples, all accurate
Unique capability B+ Integrates Landauer-aware energy + 3D thermal + inverse design + multi-paradigm + extensible registries + tech roadmap in one workflow. Individual capabilities exist elsewhere; the combination and accessibility are new.
OSS readiness Validated for architecture-stage engineering 800+ checks against 12 production chips (82), 21 materials (192), JEDEC θ_jc measurements, published IR thermal data, HotSpot benchmarks, 3 hardware correlation cases, 6 external analytical benchmarks, and textbook analytical solutions. Suitable for thermal design-space exploration, material comparison, cooling-strategy tradeoffs, and architecture-stage decision support. Hardware-correlated against 3 published chip designs with documented residuals.

Bottom line: Aethermor integrates inverse thermal design, Landauer-aware energy models, heterogeneous SoC analysis, and multi-paradigm comparison into a single open-source toolkit. A hardware researcher can use it to explore material selections, cooling architectures, paradigm crossovers, density limits, and optimal power distributions — work that normally requires configuring multiple separate tools or writing custom scripts.

308 unit tests pass, 133 physics cross-checks verify every model against published data (CODATA, CRC Handbook, ITRS/IRDS), 20 literature cross-checks validate against textbook solutions, 82 chip thermal database checks cover 12 production chips across 4 market segments, 192 material cross-validation checks verify 21 substrates against 3+ independent reference sources, 33 real-world chip validation checks confirm thermal predictions for 4 published chip designs (NVIDIA A100, Apple M1, AMD EPYC 9654, Intel i9-13900K), 18 experimental measurement checks validate against JEDEC θ_jc data, published IR thermal imaging, and HotSpot benchmarks, and 23+ engineering case study checks verify decision-driven workflows. Limitations are honestly documented.

The project is validated for architecture-stage engineering: cross-checked against published hardware measurements across 12 production chips and 21 materials (800+ independent checks). Hardware-correlated against 3 published chip designs (A100, i9-13900K, M1) with Yovanovich (1983) spreading resistance and full gap analysis; A100 θ_jc within 2%, i9 T_j within +9 K, M1 T_j within measured range (+5 K). See docs/HARDWARE_CORRELATION.md. Suitable for substrate selection, cooling tradeoffs, density limits, paradigm crossover analysis, and architecture-stage thermal engineering.