Morning Edition · Tuesday, August 4, 2026Published at 2:03 AM EDT · New York

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.

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…