New paper details how mold achieves its linker speedups
A newly published paper on mold, the massively parallel linker, is drawing discussion on r/programming.
R/PROGRAMMING (TOP) — Its ablation study finds that speed gains do not come from any single optimization, but from running every linking pass in parallel at once. Commenters note speedups up to 112x and hope the tech reaches MSVC.
A research paper about mold, the massively parallel linker created by Rui Ueyama, is circulating on r/programming and has sparked a lively discussion about why the academic write-up arrives years after the tool itself.
One finding from the paper draws particular attention: the ablation study rules out any single optimization as the primary driver of performance. Instead, running all linker passes in parallel simultaneously accounts for the gains, a point commenters highlight as a genuinely useful insight for systems design.
Numbers circulating in the thread cite speedups of up to 112x compared to traditional linkers, prompting jokes that C++ is approaching JIT-like iteration speeds.
Some commenters wonder why a preprint was not posted to arXiv years ago; others reply that producing rigorous, comparable performance research takes time, especially against mature projects. There is also speculation about whether the techniques, or mold itself, will ever arrive for Windows MSVC builds.
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