nitai108 's List: Computers & Brains

The difference between brains and computers arises not so much in the size of the elementary computer elements as in their numbers: where a modern microprocessor chip has 10⁹ transistors, the human brain contains about 10¹⁴ [100 trillion] synapses (and a brain uses about as much power as a microprocessor).  A state of-the-art microprocessor could have close to 30 km of total wire connecting its transistors, where the brain has 3 to 4 x 10⁵ km of wire (most of which is axons).  The brain’s total wire, then, is about the same as the mean distance from the earth to the moon (a little less than 4 × 10⁵ km).  Clearly, although the sizes of the basic computer elements are not so different between brains and computers, what is vastly (a million fold) different is the number of elements.

the brain has over three times as many synapses per microliter (a billion) as a modern computer chip with 300,000,000 transistors per microliter.  Brains also have wires (neurons) that are 10 times shorter, on average, as those on computer chips