Earlier quoted context omitted.
The biggest GPT2 (1.5B params) takes about 10GB VRAM, meaning it runs on a RTX 2080 TI, or the 12GB version of the RTX 3080
What's the largest language model I can run on a 3090 with 24 GiB RAM?
But if you are looking to get performance of ChatGPT or GPT-3 then don't waste your time, all GPT-3 like small LLM models (below at least 60B params) are useless for any real world use case, they are just toys.