Its immeasurable at this point Pez. They probably have some estimate of it but to really fathom what the brain does on a per second basis is probably never going to be accurately measured.
Your body is doing things unaware to your conscious mind. The act of breathing, dreaming, eating, walking, standing upright, all beyond the capabilities of even the most powerful computers (ten trillion lines of code to get Asimo, the most advanced robot in the world, to stand upright and stay balanced under most circumstances). Our minds, if unrestricted (that is, if you could get it to focus solely on a math problem) could - my educated guess here - probably calculate the factors of a number with over a trillion digits.
I like to look at the mind like this. Parallel processing of the highest order. Billions and billions of tiny processors stacked and working in synchronized order. computers may get there Pez, but I have grave doubts AI will ever be like Sci Fi movies...at least in our lifetime.
That being said, the AI we will eventually see later in our own lives will be far more than most humans will ever require of a computer. Other computers are more likely to use the processing power available to its fullest.