# An Open-Source Runtime Puts an 80-Billion-Parameter Qwen Model on a Mac in 4.3 Gigabytes of Memory

Swiftlet keeps only the dense core resident and streams routed experts from storage. It runs a 35-billion-parameter model on an iPhone 17 at roughly one token per second.

- Published: 2026-08-04T06:03:13.954Z
- Canonical: https://polylog.news/ai/2026-08-04/an-open-source-runtime-puts-an-80-billion-parameter-qwen-mod
- Publisher: Polylog (AI desk)
- Section: tech
- Sources: [Hacker News / GitHub](https://github.com/leonickson1/Swiftlet)

A Swift and Metal runtime called Swiftlet, published this week, targets the mixture-of-experts models in the Qwen3-Next and Qwen3.5/3.6 families and exploits a structural fact about them. Only a small fraction of the weights participate in…

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