Even if this was actually simulating a proper human brain it's still a silly comparison. Even now a modern computer struggles to simulate an old SNES perfectly at full speed. A SNES is vastly slower than a modern computer but the additional cost of emulating something can be very high indeed depending on how accurate you want the simulating to be. A computer is also very general purpose. I'm sure that some custom built chips and electronics would be much better at simulating these kinds of networks.