Local AI Development with Qwen3.6-27B and Opencode on a 5090

A developer who previously dismissed local LLMs as 'not up to standards' compared to cloud offerings like Claude Code or Cursor recently switched to a fully local setup. Using Opencode + llama-server + Qwen3.6-27B at a reasonable quantization with 128K context, running on a single RTX 5090 in a dedicated Linux box. The setup serves over the network to their main dev machine.

Key Details

• Tooling: Opencode (frontend) + llama-server (backend) + Qwen3.6-27B model
• Hardware: 1× RTX 5090, dedicated Linux machine
• Context length: 128K tokens (user unsure if it can be pushed further, but found it sufficient)
• Performance: Not perfect — occasional loops require manual interruption — but overall 'very worthwhile'

Motivation

The switch was driven by increasing usage constraints and 'enshittification' of cloud plans. Local setup eliminates worries about usage limits, prompt analysis, or account bans — particularly important for security research, scraping, or other activities that might trigger cloud provider scrutiny.

Who It's For

Developers on the fence about local AI coding agents, especially those who have been skeptical about local model quality or who need to avoid cloud account risks. If you have a powerful GPU (e.g., RTX 5090), the experience is now competitive with cloud tools.

Bottom Line

The user reports 'immensely freeing' experience despite occasional hiccups, and believes local AI development has reached the point where it's 'very worthwhile indeed.'