Recall that GPT2030 could do 1.8 million years of work[8] across parallel copies, where each copy is run at 5x human speed. This means we could simulate 1.8 million agents working for a year each in 2.4 months.
You point out that human intervention might be required every few hours, but with different time zones, we could at least have the GPT working twice as many hours a week as humans, so that would imply ~1 month above. As for the speed now, you say about the same to three times as fast for thinking. You point out that it also does writing, but it is verbose. However, for solving problems like that coding interview, it does appear to be an order of magnitude faster already (and this is my experience solving physical engineering problems).
You point out that human intervention might be required every few hours, but with different time zones, we could at least have the GPT working twice as many hours a week as humans, so that would imply ~1 month above. As for the speed now, you say about the same to three times as fast for thinking. You point out that it also does writing, but it is verbose. However, for solving problems like that coding interview, it does appear to be an order of magnitude faster already (and this is my experience solving physical engineering problems).