The Automated LLM Speedrunning Benchmark: Reproducing NanoGPT Improvements
Abstract
Rapid advancements in large language models (LLMs) have the potential to assist in scientific progress. A critical capability toward this endeavor is the ability to reproduce existing work. To evaluate the ability of AI agents to reproduce results in an active research area, we introduce the Automated LLM Speedrunning Benchmark, leveraging the research community contributions on the NanoGPT speedrun, a competition to train a GPT-2 model in the shortest time. Each of the 19 speedrun tasks provides the agent with the previous records training script, optionally paired with one of three hint formats, ranging from pseudocode to paper-like descriptions of the new records improvements. Records execute quickly by design and speedrun improvements encompass diverse code-level changes, ranging from high-level algorithmic advancements to hardware-aware optimizations. These features make the benchmark both accessible and realistic for the frontier problem of improving LLM training. We find that recent reasoning LLMs combined with SoTA scaffolds struggle to reimplement already-known innovations in our benchmark, even when given detailed hints. Our benchmark thus provides a simple, non-saturated measure of an LLMs ability to automate scientific reproduction, a necessary (but not sufficient) skill for an autonomous research agent.
Keywords
Cite
@article{arxiv.2506.22419,
title = {The Automated LLM Speedrunning Benchmark: Reproducing NanoGPT Improvements},
author = {Bingchen Zhao and Despoina Magka and Minqi Jiang and Xian Li and Roberta Raileanu and Tatiana Shavrina and Jean-Christophe Gagnon-Audet and Kelvin Niu and Shagun Sodhani and Michael Shvartsman and Andrei Lupu and Alisia Lupidi and Edan Toledo and Karen Hambardzumyan and Martin Josifoski and Thomas Foster and Lucia Cipolina-Kun and Abhishek Charnalia and Derek Dunfield and Alexander H. Miller and Oisin Mac Aodha and Jakob Foerster and Yoram Bachrach},
journal= {arXiv preprint arXiv:2506.22419},
year = {2025}
}