We are far from having a model of how the brain really works.
Furthermore, i know it's a really common analogy but the brain is not really comparable to a computer. The brain is not programmable, it only have a single function which is "given x input, what output is more likely to keep the organism alive and well". It's a complex task, for sure.
But that's not a computer.
A computer is a machine on which you can run arbitrary programs. I can't plug some wires in your brain and program it to do what I want. It's not that the sockets for my wires are missing, it's just that the physical structure doesn't allow generic computing. If you really wanted to make an analogy, you could say that the brain is an electric circuit. You cannot program an electric circuit. It does what it's wired to do. You can't say that your electrical circuit is faster than a computer. It makes no sense.
So it's a false assumption to say that brains are faster than computers because it's just something that you cannot compare.