After testing the top-tier M5 Ultra Mac Studio with 256 GB RAM, I can confirm it's a dream machine for local AI agents. It runs personal assistants like Open Claw and Hermes Agent with impressive speed and zero cloud costs, changing perceptions about local vs. cloud model performance.

Compared to the M3 Ultra (512 GB RAM) and a desktop PC with an RTX 5090, the M5 Ultra excels in size, price, thermals, and unified memory architecture. While the 5090 retains a memory bandwidth edge, the Mac Studio's silent operation, macOS ecosystem, and app vibrancy make it preferable for daily use.

Running Qwen3.8-Flash-Next locally has become my default in Open Minis for iOS and Hermes Agent, surpassing even Siri AI. Agents respond faster, handle larger context windows, and sustain multi-turn loops without slowdown. I've also integrated local models into the Codex app, orchestrated by GPT-6 Astra, with excellent results.

As a tinkerer, not an AI developer, I've adopted local AI for privacy, cost control, and the "cool factor." This summer, my iOS 27 review workflow for Mac Stories was powered entirely by local AI on this hardware.