Same Model, Same Server, Different Harness: PI Agent Beat OpenCode Badly on Qwen3.8-27B

r/LocalLLaMA·medium signalXBlueskyLinkedInCopy link

An r/LocalLLaMA test (160 upvotes, 108 comments) ran Qwen3.8-27B Q4_K_M through llama-server on an RTX 3090 and compared PI Agent against OpenCode on the classic bouncing-ball animation task. PI Agent produced better output while using fewer tokens, running faster, and avoiding OpenCode's hard 32k output cap and freezes. The concrete difference is compaction timing: with a 100k context and 32k output set, OpenCode starts compressing at 67k while PI Agent holds to 90k. For local-model users the harness is now as much of a variable as the model.