Yeah it wouldn't fit. GPT3 is 175B params, so even if you use 8 bit for each weight, you need 175×10^9÷2^30 = 163GiB of memory.
>It's around 500gbs and requires around 300+gbs of vram from my understanding and runs on one of the largest super computers in the world. Sable diffusion has around 6 billion parameters gpt-3/chatgpt has 175 billion.