Fabian G. Williams aka Fabs

Fabian G. Williams

Principal Product Manager, Microsoft Subscribe to my YouTube.

I Added a Second Local Agent This Week. Here Is the Receipt for Every Human Decision Behind It.

I trialed a second local coding agent, Hermes from Nous Research, on my own MacBook, pointed at the same local Qwen 3.8 model I already run. Installed additively so nothing already working could break, governed with manual approvals, then tested until it proved it behaves. Here is the trial, in tables and screenshots, plus a receipt for the human hours behind writing it up.

Fabian Williams

7-Minute Read

The Hermes agent running against a local Qwen3.8-27B MLX server, with the Apple M3 Max GPU pinned at 97 percent on the first turn

This week I trialed a second local coding agent, Hermes from Nous Research, on my own MacBook Pro M3 Max, pointed at the same local Qwen 3.8 model I already run. I installed it additively, so nothing already working could break, governed it with manual approvals, and did not stop until it proved it behaves. Here is the trial, in tables and screenshots.

Two Agents, One Local Model: Do They Run in Parallel, or Take Turns? I Measured It.

A reader asked what happens if I run two local coding agents against the same Qwen 3.8 model on one Mac at the same time. I thought I knew the answer. I was wrong. So I read the server source, wrote a barrier-synchronized load driver to remove the human-ordering bias, and measured it. Batching is real up to 32 wide, but it is not free, and three innocent-looking choices collapse it back to a single lane.

Fabian Williams

9-Minute Read

A line chart showing aggregate throughput rising with concurrent agents while per-agent decode rate falls, on one local MLX model

A reader on Reddit asked me a sharp question about my last post. I had trialed a second local coding agent, Hermes, pointed at the same local Qwen 3.8 model my other agent already uses. His question was simple. Did I ever run both agents at the same time, two separate harnesses hammering one model on one Mac at once. And what about Hermes spawning its own sub-agents against that same endpoint. Is any of that predictable.

I Swapped My Local Coding Model Overnight From a Hotel. The Agent Graded the Upgrade Itself.

Local models are how I run my community work, my volunteer projects, my side hustles, and my musings, for two reasons: cost and keeping client data away from the labs. A new version dropped, so I upgraded it overnight from a hotel, additively, without touching the old one. Then I handed the new model the reviews and let my OpenCode agent test its own upgrade. It stood up a throwaway server, probed itself, and found three config gaps quietly throttling it. Here is the journey, in tables.

Fabian Williams

8-Minute Read

Activity Monitor showing the M3 Max GPU pinned at 92 percent while an OpenCode agent runs probe requests against a throwaway Qwen3.8 test server on port 8082

Local models are how I run my community work, my volunteer projects, my side hustles, and my musings. Two reasons, both simple:

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