ChatGPT keeps answering as 5.5 Instant even though GPT-5.6 Sol is my default model
Set GPT-5.6 Sol as my default in settings a few days ago. Every new chat still comes back in about two seconds with the shape of answer I used to get from 5.5, and the label on the reply says 5.5 Instant, not Sol. Threads that were already on Sol stay on Sol. New ones do not.
Ruled out on my side:
- signed out and back in, same on web and in the desktop app
- cleared site data, brand new chat, same thing
- not the free tier, this is a paid account
- no custom instructions or project involved, plain new chat
What I think is happening but cannot prove: since 5.6 went generally available on 9 July, the picker is not really a model list any more, it is an effort/compute list. The Instant option runs GPT-5.5 Instant, and Medium / High / Extra High are the settings that map to Sol. Terra and Luna are not selectable in ordinary chats at all. So "default model = Sol" may be closer to a hint than a setting, and anything that looks easy starts on Instant.
Three questions:
- Is there any way to pin Sol so that a new chat never starts on Instant?
- If it escalates from Instant to something higher mid-conversation, is that visible anywhere, or do you just notice the answers got better?
- Is there a reliable way to check which model produced a specific answer, other than asking it? Asking it does not work, it will tell you anything.
@oncall_omar · 2h ago · 3 replies
The bit that trips everyone up: the picker stopped being a model picker and became a compute picker. Instant is literally GPT-5.5 Instant, the low end of the same control, not some old model you accidentally selected. Medium and above are where Sol lives.
So if your effort setting landed on Instant, or got reset to it when 5.6 rolled out, every new thread genuinely starts on 5.5 Instant and the product is doing exactly what it says, it just is not labelled the way you expect. Move the thinking level to Medium or higher and see whether the label on the next reply changes.
The other documented half: on eligible paid plans it can step up from Instant on its own when a request looks like it needs more reasoning. That is why a long, gnarly prompt sometimes feels like Sol and a one liner never does.
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@stdlib_stef · 2h ago
Worth adding that the escalation only goes upward. A short prompt that looks trivial will sit on Instant forever. If you are evaluating Sol with small test prompts you are probably not testing Sol at all, which is how half the "the new model is worse" posts get written. Make the eval prompts representative, or set the effort explicitly and stop relying on the router for anything you intend to measure.
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@integral_ines · 2h ago
Matches my account exactly. The effort control was on Instant while the default model dropdown said Sol. Two controls, one of them wins, and it is not the one with the model name on it.
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