Comment by dmos62
18 hours ago
Lack of transparency as regards "thinking power"-consistency is a big gripe of mine with LLM providers. It's even worse with ChatGPT and the like. E.g. I had to learn the hard way that at >45k input tokens ChatGPT 5.2 Thinking Extended bumps its intelligence down so hard that it can't follow basic instructions (or it somehow truncates the input, losing the instructions). It sucks to lose confidence in an otherwise great tool. I would 100x prefer being forced to back-off, or getting a straight-no, than getting silently downgraded. Transparency is a big deal.
Sounds like you ran into the Maximum Effective Context Window: https://arxiv.org/abs/2509.21361?context=cs.AI
Interesting article. Not sure it's the same phenomenon. What I experienced was like a day and night difference when you go from 44.5k to 45.5k. Didn't notice any fluctuation to suggest that it's no a hard 45000 limit. I ran many many queries, similar problem space, but the problems varied a lot.