[jankovicsandras]

Here's a completely made up point of view. (I haven't read the articles.)

GPT-4 is not an LLM, but a complex software system, which has LLM(s) at its core, but also other components like RAG, toxicity filter, apologizing mechanism, expert systems, etc. "GPT-4" is product name / marketing name. For OpenAI, this would be logical for performance and business reasons. This explains also how they can tune it, the apparent secrecy about the architecture, etc.

It's also logical to make small, incremental changes to this system instead of building whatever GPT-5 would mean from ground up. So I expect "GPT-5" is also just a marketing name for a slightly better black-box (for us) system and product line.

[ericlewis]

ChatGPT is in-fact that. GPT-4 the API is not that. There is clearly no RAG, you bring that yourself, same with toxicity filtering, again - a different api, up to you to implement. etc. There is probably something going on before the input reaches GPT-4 and we are definitely not seeing the raw output from the LLM. But the layers over GPT-4 the API are thinner than ChatGPT.

The Assistants API is closer to ChatGPT & what you are describing.

Edit: it should be noted that the Assistants API is somewhat model agnostic as well, so the product part of this isn't part of the inference system.

[iLoveOncall]

That would make a lot of sense if open source models didn't output stuff pretty much exactly the same way as OpenAI's models.

[meiraleal]

GPT-4 leap from GPT-3 is like you said. GPT-5 might be another leap that we can't predict.