Interestingly, this transformer architecture was actually ... OpenAI released a larger and more capable model, called GPT-3, in June 2020, but it was the full arrival of ChatGPT 3.5 in November ...
The Transformer deep neural network architecture ... GPT-2 (2019) has 1.6 billion parameters; GPT-3 (2020) uses 175 billion parameters; and PaLM (2022) has 540 billion parameters.