GPT-3.5 is up to 175B parameters, GPT-4 (which is what OP is asking for) has been speculated as having 1T parameters, although that seems a little high to me.

GPT-3.5 is up to 175B parameters, GPT-4 (which is what OP is asking for) has been speculated as having 1T parameters, although that seems a little high to me. It's easy to run a much worse model on much worse hardware, but there's a reason why it's only companies with huge datacenter investments running the top models.