what's the difference between Sol Ultra and Sol pro? is pro a thing of the past now

Ultra = parallel subagents with max reasoning

Pro = test-time compute (best of N responses)

prideout 4 hours ago | parent | next [-]

Confused about how to access Ultra; I don't see it in on their plans page.

	▲	prideout 4 hours ago \| parent [-]
		Ah, I see it as a "reasoning level" in codex after typing /model

why would you use one over the other?