I bought a fully kitted out Apple Macbook Pro to do local AI development. I’ve been buying a decent amount of tokens to justify an ROI. I heard all the buzz about Qwen3.8-27B being near Anthropic Opus quality so I decided to try it. Before I get into the details, this is not how I normally use AI coding tools. This was meant to be a test of how someone that doesn’t know anything about software engineering would vibe code Pacman. Here’s the screenshot of the javascript app it built.
Macbook Pro Specs: M5 Max, 128GB ram, 8TB ssd. Mac OS 26.6.2. Installed Homebrew, Claude Code, VS Code. Time to start my agentic testing…
ollama launch claude --model qwen3.8:27b-mlx
The prompt:
This is an agentic coding test to see how well a local LLM can implement the arcade game Pacman. You can chose the tech stack and strategy to implement. I want you to work fully autonomous.
Shit went south fast. First there was a kernel panic that caused a reboot. I thought that might be some one-off since I still had over 64GB of free memory. Then it happened again, and again, and again. I’ve earned my greybeard status and had a hunch the “video memory” was leaking and going corrupt. I was fortunate that it happened once while I was watching the screen flash green and some other artifacts before the OS tossed in the towel.
That was enough for me to get my search/chat-fu going to find a confirmation: IOGPUMemory Crash. That’s unfortunate because I was looking forward to the 262KB Qwen3.8-27B context window.
Claude code was also dogshit slow. I specifically spec’d the M5 Max cpu because of the 614GB/s memory bandwidth. You want fast ass memory bandwidth when running inference. What was happening is the reasoning was defaulting to extra high and generating a bunch of reasoning tokens.
Here’s my strategy to “fix.”
- Reduce the context window. I going to try 128KB and manage context growth by using subagents.
- Change the effort in Claude Code to medium