In 2009, the Brazilian scientist Suzana Herculano-Houzel performed a review of what we know about the physical structure of the brain. The adult human male brain has 86 billion neurons–more than any other primate. Each neuron has between 1,000 to 10,000 synapses that result in 125 trillion synapses in the cerebral cortex alone. That is at least 1,000 times the number of stars in our galaxy. Stephen Smith from Stanford University reported that one synapse might contain some 1,000 molecular-scale switches. That is over 125,000 trillion switches in a single human brain.
Compare the switching capacity of the brain to that of the most complex commercially available computer processor – which is the 7.2 billion transistor Intel Broadwell-EP Xeon (2016). The human brain has approx. 17 million times more switching capacity than the most powerful computer processor you can buy today. That doesn’t even include the full structure of the brain or the possible quantum effects of neuron Microtubules argued by Stuart Hameroff, Roger Penrose and others.