It seems like GPT-4 is going to be coming out soon and, so I've heard, it will be awesome. Now, we don't know anything about its architecture or its size or how it was trained. If it were only trained on text (about 3.2 T tokens) in an optimal manner, then it would be about 2.5X the size of Chinchilla i.e. the size of GPT-3. So to be larger than GPT-3, it would need to be multi-modal, which could present some interesting capabilities.
So it is time to ask that question again: what's the least impressive thing that GPT-4 won't be able to do? State your assumptions to be clear i.e. a text and image generating GPT-4 in the style of X with size Y can't do Z.
This appears to be right.
Here's what I got when I asked it to work out 12345 x 13579 step by step:
1 6 7 4 6 1 6 0 5