I think you mean GPT-4 since Chinchilla is a Deepmind project. But yes, I was also suspecting that also as it seems unlikely this was the full 175b parameter model with such big improvements in speed and price.
In fact, given the pricing for OpenAI Foundry, that seems even more likely as this GPTTurbo model was listed along with two other models with much larger context windows of 8k and 32k tokens.
"Brockman says the ChatGPT API is powered by the same AI model behind OpenAI’s wildly popular ChatGPT, dubbed “gpt-3.5-turbo.” GPT-3.5 is the most powerful text-generating model OpenAI offers today through its API suite; the “turbo” moniker refers to an optimized, more responsive version of GPT-3.5 that OpenAI’s been quietly testing for ChatGPT." [0]
Chinchilla optimization is a technique which can be applied to existing models by anyone, including OpenAI. The chatGPT API is not based on GPT-4.
I just meant chinchilla optimal in terms of the corrected scaling curves from the chinchilla paper. The original GPT-3 was way larger than it needed to be for the amount of data they put into it based on the curves from the chinchilla paper.
In fact, given the pricing for OpenAI Foundry, that seems even more likely as this GPTTurbo model was listed along with two other models with much larger context windows of 8k and 32k tokens.