증거 - Opus 5.5 출시 당일 vs 오늘, 동일 프롬프트 사용 시 성능 저하 (Godot 엔진)
Evidence - Opus 5.5 today vs launch regression with same prompt (Godot Engine)
핵심 요약
사용자가 Opus 5.5의 성능 저하를 주장하며 동일 프롬프트 결과를 비교했으나, 커뮤니티는 표본 부족과 확률적 모델 특성을 이유로 비판하고 있습니다.
- 성능 저하 주장 — 출시 당일과 비교해 코드 품질 및 물리 엔진 구현이 퇴보했다고 주장함
- 표본 부족 논란 — 단 2회의 테스트만으로는 모델 성능 변화를 입증하기 어렵다는 지적이 많음
- 확률적 특성 — LLM은 비결정론적 모델이므로 동일 프롬프트라도 결과가 다를 수 있음을 간과함
- 검증 방식 비판 — 다수의 테스트와 통계적 접근 없이 단일 비교만으로는 증거가 될 수 없다고 반박함

On launch day Opus 5.5 kindly took up residence on my Mac. I ran some tests before trusting it on my big projects, it passed with flying colours. Lander, a game by Elite creator David Braben holds a special place in my soul due to it being the first game I played at school in the UK. With a cutting edge 3D engine for 1990 running on an Acorn Archimedes with RISC architecture (the first ARM chips) - what a time to be a young kid interested in computers.
With Opus 5.5 I want to recreate it faithfully, short draw-distances and all.
Well dear Claude I’ve been keeping receipts.
In my notes, the exact prompt * and two original reference images of Lander. The resulting one-shot Godot repo (Mac OS, Metal rendering, C#) from 23rd September is kept separate on disk and isn't used as a reference.
Today, 2nd October, in a fresh workspace from scratch the same prompt and reference images we fed in again.
The result is truly depressing. Lander by gimped 5.5 has no redeeming features compared to the original day zero version. The regressions:
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A serious rendering glitch * that isn’t in the original - as the camera moves, the scenery props snag and glitch vs world space.
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No spacecraft break-apart physics, the original implemented this ‘nice extra’ which wasn't specifically asked for in the prompt
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No introductory controls menu, only a small text line permanently visible over the world view
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An inferior look to the launch pad turrets - students and road users may recognise them!
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When shooting, bullets are less accurately rendered when the craft moves, they also appear to spawn at the back of the craft and no-clip through

