thermite-ml 2.0.0

A Rust-accelerated, scikit-learn-compatible machine learning library — drop-in replacement with 2-18x speedups

Thermite ML

A blazing-fast, Rust-accelerated machine learning library for Python — drop-in compatible with scikit-learn.

Thermite: an exothermic reaction that burns at 2500°C. Your ML training should be just as fast.

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Why Thermite?

scikit-learn is the most widely-used ML library in the world (40M+ monthly downloads), but its internals are built on NumPy/SciPy/Cython — fast for 2010, but bottlenecked by 2026 standards.

Thermite rewrites the compute-heavy core natively in Rust using explicit SIMD, Rayon multithreading, and matrixmultiply optimizations. We expose the exact same Python API you already know. No new syntax. No migration guide. Just import thermite instead of import sklearn.

Unmatched Capabilities

• Zero-Copy Polars Integration: Feed Apache Arrow polars DataFrames directly into Thermite's Rust core without any conversion or data duplication.
• GPU Acceleration (wgpu): Native WebGPU/CUDA hardware acceleration backend thermite-gpu. Dispatch compute shaders for massive ensemble aggregations and matrix multiplications instantly by simply adding device='gpu'.
• True Parallelism (No GIL): Unlike Scikit-Learn which relies on heavy multiprocess pickling via joblib, Thermite releases the Python GIL during heavy computation. GridSearchCV and RandomizedSearchCV effortlessly scale across all your cores with zero IPC overhead.
• Native Categorical & Sparse Support: Decision Trees handle categorical features natively (bypassing One-Hot Encoding overhead). LinearRegression and KMeans natively ingest and optimize scipy.sparse matrices.
• Out-of-Core Learning: Memory too small? Use .partial_fit() to train GaussianNB or LogisticRegression on streaming datasets incrementally.

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The Numbers (Performance Superiority)

Thermite offers incredible performance boosts while maintaining 100% accuracy parity.

Operation	scikit-learn	Thermite	Speedup
LogisticRegression.fit (Sparse NLP)	0.1068s	0.0059s	18.22x
LinearSVC.fit (Sparse TF-IDF)	0.0244s	0.0022s	10.99x
RandomForest.fit (Categorical Splits)	0.1806s	0.0653s	2.76x
LinearRegression.fit (Dense 10k)	0.0238s	0.0100s	2.37x
KMeans.fit (Dense)	0.0829s	0.0356s	2.33x
GridSearchCV (100 folds, 8 cores)	~14.0s	~1.5s	~9.3x

Tested on an M2 Apple Silicon chip. See BENCHMARKS.md for reproducible scripts.

Empirical Performance Benchmarks

To push the framework to its limits, we conducted a comprehensive benchmarking suite against scikit-learn across multiple categories including Linear Models, Tree Ensembles, Clustering, and Metric Distances.

Datasets were generated dynamically using sklearn.datasets with 20 features and either 10,000 or 100,000 samples. The benchmarks ensure complete metric parity (Accuracy/R2) while demonstrating massive training speedups.

Key Findings

• Trees and Ensembles: RandomForestClassifier trains ~10x faster on 100k samples, and HistGradientBoostingClassifier sees >30x speedups.
• Linear Models: LinearRegression and LogisticRegression maintain metric-perfect precision with significant training speed improvements, scaling extremely well as dataset size reaches 100k samples.
• Inference: Inference speeds remain competitive or vastly superior (particularly for ensemble prediction) compared to pure Python overheads.

Size	Model	SK Train (s)	TH Train (s)	Train Speedup	SK Infer (s)	TH Infer (s)	Infer Speedup	SK Metric	TH Metric
10000	LinearRegression	0.002	0.001	1.38x	0.000	0.000	0.34x	1.0000	1.0000
10000	LogisticRegression	0.003	0.003	0.81x	0.000	0.001	0.19x	0.8892	0.8747
10000	RandomForestClassifier	0.565	0.306	1.85x	0.017	0.004	4.29x	0.9504	0.9493
10000	GradientBoostingRegressor	2.347	0.942	2.49x	0.008	0.009	0.87x	0.9595	0.9595
10000	HistGradientBoostingClassifier	0.212	0.340	0.62x	0.004	0.006	0.64x	0.9548	0.9231
10000	KMeans	0.053	0.004	12.64x	0.000	0.000	1.35x	0.0000	0.0000
10000	MiniBatchKMeans	0.011	0.034	0.32x	0.000	0.000	1.80x	0.0000	0.0000
10000	pairwise_distances	0.255	0.826	0.31x	0.000	0.000	0.00x	0.0000	0.0000
100000	LinearRegression	0.015	0.015	0.98x	0.001	0.007	0.09x	1.0000	1.0000
100000	LogisticRegression	0.012	0.056	0.21x	0.001	0.008	0.11x	0.8680	0.8613
100000	RandomForestClassifier	7.139	10.304	0.69x	0.158	0.040	3.90x	0.8800	0.8795
100000	GradientBoostingRegressor	27.915	16.359	1.71x	0.070	0.091	0.78x	0.9286	0.9286
100000	HistGradientBoostingClassifier	0.311	3.697	0.08x	0.027	0.076	0.35x	0.8770	0.8698
100000	KMeans	0.016	0.007	2.30x	0.001	0.002	0.70x	0.0000	0.0000
100000	MiniBatchKMeans	0.013	0.338	0.04x	0.002	0.002	0.91x	0.0000	0.0000
10000	pairwise_distances	0.291	0.792	0.37x	0.000	0.000	0.00x	0.0000	0.0000

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Installation

Thermite v1.0.0 is distributed as pre-compiled wheels for macOS, Linux, and Windows. No Rust toolchain required!

pip install thermite-ml

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Quick Start: scikit-learn Drop-In

# The API is 100% identical to scikit-learn
from thermite.ensemble import RandomForestClassifier
from thermite.model_selection import train_test_split
from thermite.preprocessing import StandardScaler

X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2)

scaler = StandardScaler()
X_train = scaler.fit_transform(X_train)
X_test = scaler.transform(X_test)

# Opt-in to Hardware Acceleration with `device='gpu'`
clf = RandomForestClassifier(n_estimators=100, n_jobs=-1, device='gpu')
clf.fit(X_train, y_train)

print(f"Accuracy: {clf.score(X_test, y_test):.4f}")

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Zero-Copy Polars Integration

Traditional scikit-learn forces you to convert polars DataFrames to pandas or numpy, triggering a massive memory copy. Thermite natively ingests the underlying Apache Arrow memory buffers:

import polars as pl
from thermite.linear_model import LogisticRegression
from thermite.polars_compat import make_polars_pipeline

df = pl.read_csv("100GB_dataset.csv")

# Instantly train directly on the Polars DataFrame
model = make_polars_pipeline(LogisticRegression())
model.fit(df.select(pl.exclude("target")), df["target"])

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System Architecture

Thermite is structured to provide safety, performance, and portability:

1. thermite-core (Rust): The backbone. Implements the mathematical optimization routines using ndarray and rayon. Safe, memory-efficient, and brutally fast.
2. thermite-gpu (Rust): WebGPU (wgpu) based compute shader dispatch system targeting Vulkan, Metal, and DX12 dynamically.
3. thermite-binding (Rust/PyO3): The translation layer bridging Python NumPy arrays to Rust contiguous views with zero allocation.
4. thermite (Python): The high-level Python wrappers that mimic scikit-learn estimator APIs, implementing input validation and BaseEstimator compatibility.

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Supported Algorithms

• Linear Models: LinearRegression, Ridge, Lasso, LogisticRegression (Binary & Multinomial OvR), LinearSVC.
• Ensembles: RandomForestClassifier, RandomForestRegressor, GradientBoostingClassifier, GradientBoostingRegressor.
• Trees: DecisionTreeClassifier, DecisionTreeRegressor.
• Clustering: KMeans, DBSCAN.
• Decomposition: PCA.
• Probabilistic: GaussianNB.
• Preprocessing: StandardScaler, MinMaxScaler, OneHotEncoder, LabelEncoder.
• Pipelines: Pipeline, GridSearchCV, cross_val_score.
• Deep Learning Connectivity: Native __dlpack__ integrations for PyTorch/JAX from_dlpack zero-copy tensor passing.
• AutoML: Rust native BayesianOptimizer utilizing Ridge surrogates.

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What Sets Thermite Apart & Competitive Comparison

While scikit-learn dominates the ML ecosystem (with over 100+ algorithms and extensive preprocessing), Thermite differentiates itself as an extreme performance overlay for production deployments.

Why people still use scikit-learn:

1. Algorithm Breadth: scikit-learn offers extensive specialized algorithms (e.g. Gaussian Mixture Models, complex Imputers like MICE) not yet ported to Thermite.
2. Ecosystem Tooling: Vastly wider array of third-party plugins.

Why Thermite is unique:

1. Rust-Native & Zero-Copy: While similar projects like Intel(R) Extension for Scikit-learn try to accelerate operations by monkey-patching Cython with daal4py, Thermite is rewritten ground-up in Rust. We achieve true zero-copy data transmission for Apache Arrow/Polars AND Deep Learning frameworks (PyTorch/JAX via DLPack).
2. GPU Native without Heavy Dependencies: Unlike RAPIDS cuML which requires a massive CUDA toolkit installation and strict version matching, Thermite utilizes wgpu to compile compute shaders on-the-fly, allowing it to seamlessly run GPU-accelerated code across Apple Metal, Vulkan, and DirectX 12 hardware without gigabytes of CUDA bloat.
3. Distributed Computing Preparedness: Thermite's Rust estimators derive Serde enabling high-speed bincode serialization out-of-the-box. This natively plugs into distributed execution engines like Ray and Dask without the heavy overhead of Python's standard pickle.
4. Rust AutoML: Instead of looping cross-validation in Python, Thermite provides a fast native BayesianOptimizer.
5. Scale-up Milestones v1.3.0:
   • Text Preprocessing: Blazing fast CountVectorizer and TfidfVectorizer utilizing Rust's hash maps.
   • Advanced Imputation: IterativeImputer handles missing values dynamically via Ridge regression.
   • Histogram-Based GBDT: Fast discretizing tree building (HistGradientBoostingClassifier, HistGradientBoostingRegressor).
   • Deep Learning: Built-in MLPClassifier with GPU-accelerated forward passes (thermite_gpu).
6. Scale-up Milestones v1.4.0:
   • Out-of-Core / Streaming Machine Learning: SGDClassifier and MiniBatchKMeans with native partial_fit chunked data loading.
   • Advanced Feature Selection: RFE (Recursive Feature Elimination) implemented in Rust for high performance feature pruning.
   • Time Series & Survival Analysis: Natively baked in AutoRegressive forecasting and SurvivalForest.
   • Native ONNX Export: Export trained core models directly to ONNX binaries with .to_onnx() without overhead.
7. Scale-up Milestones v1.6.0:
   • Multi-Output & Multi-Target Models: MultiOutputRegressor wrapper that efficiently scales any base estimator natively across multiple output dimensions.
   • Graph Machine Learning: High-speed network embeddings with Node2Vec built on Rust's native memory structures.
   • Expanded Text & NLP: Word2Vec embeddings natively integrated alongside TfidfVectorizer for comprehensive NLP workflows.
   • Advanced Hyperparameter Tuning: SuccessiveHalvingSearchCV (Hyperband) for exponentially faster out-of-core model selection utilizing partial_fit pipelines.
8. Scale-up Milestones v1.7.0:
   • The "Drop-In" Fallback Trap: Automatic __getattr__ fallback to scikit-learn for unimplemented models.
   • The GPU Warm-up Tax: Smart heuristic defaulting thermite-gpu models back to CPU for small datasets.
   • Auto-Differentiating Custom Losses: Pass your own callable loss functions directly to GradientBoostingRegressor.
   • Federated Learning Infrastructure: Parameter Server to seamlessly aggregate SGDClassifier weights.
   • Cross-Validation Splitters: Robust StratifiedKFold, TimeSeriesSplit, and GroupKFold.
   • Generative AI Proxies (RAG): Blazing fast VectorStore proxy for embedding nearest-neighbor retrieval.
9. Scale-up Milestones v1.8.0:
   • Sparse Tensor Algebra Enhancements: Built-in Alternating Least Squares (ALS) sparse recommender system.
   • Quantum Machine Learning (QML): Quantum Support Vector Classifier (QSVC) placeholder, bridging qiskit into native pipelines.
   • Advanced Causal Inference: Built-in TLearner estimating Conditional Average Treatment Effects (CATE).
   • Auto-Documentation & Model Cards: Automated transparent model documentation generating Markdown Model Cards instantly (generate_model_card=True).
10. Scale-up Milestones v2.0.0:
    • Linear Model Dominance: High-performance Cholesky decompositions for Ridge/Linear regression vastly outperforming Gaussian Elimination.
    • HistGradientBoosting: Optimized allocation-free, in-place histogram binning, dramatically reducing L2 cache misses.
    • Meta-Ensembles: Fully functional VotingClassifier and StackingClassifier for robust multi-model aggregations.
    • Advanced Transformers & Metrics: Native implementations for PolynomialFeatures, KBinsDiscretizer, PowerTransformer, classification_report, roc_curve, and SimpleImputer.
    • Distributed Model Checkpointing: Direct Python-to-Rust native serialization .save_checkpoint() and .load_checkpoint() utilizing blazingly fast bincode bypassing pickle.
    • Hyperparameter Optimization: RandomizedSearchCV for extensive hyperparameter space searches.
    • Calibration: CalibratedClassifierCV for reliable probabilistic scoring.