Interactive demo

The SIMPLE Law for Energy Cost of LLM Inference

An architecture-aware analytical model of the energy spent on each generated token, fitted on an NVIDIA H100 with TensorRT-LLM.

SIMPLE Law

Prefill Amortization
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Decode Accum. KV-cache
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Decode Accum. Next-token
hidden size layers KV-head ratio input / output tokens

Fitted parameters

Etok in J/token.

Component breakdown at the selected τin

Etok over input and output tokens

The contour map shows the total energy per token for the current architecture; the dashed line marks the selected τin.

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Model

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Architecture

About the SIMPLE Law

The SIMPLE Law is an architecture-aware analytical model that predicts the energy consumed per generated token (Etok) during LLM inference from a model's architecture (d, L, nq, nkv) and its input and output token counts (τin, τout). This demo plots the SIMPLE Law's prediction and the share of each of its terms. Select one of the models validated in the paper, or load the architecture of any dense decoder-only Transformer (up to approximately 20B parameters) from Hugging Face.

The SIMPLE Law was fitted using this dataset.

For the complete methodology, experimental validation, and citation information, see the paper: The SIMPLE Law for Energy Cost of LLM Inference.

Authors

Citation

@misc{cavagna2026simplelawenergycost,
    title={The SIMPLE Law for Energy Cost of LLM Inference},
    author={Hiari Pizzini Cavagna and Andrea Proia and Daniele Cesarini and Zeynep Kiziltan and Andrea Bartolini},
    year={2026},
    eprint={2611.03330},
    archivePrefix={arXiv},
    primaryClass={cs.AI},
    url={https://arxiv.org/abs/2611.03330},
}

Web demo developed with the assistance of Claude (Anthropic), an AI assistant.