The human brain performs a phenomenal amount of computation. Hardware overhang refers to the extent to which available hardware will accelerate the performance of smarter-than-human AI when smarter-than-human AI is developed.
Number of transistors manufactured in 2014: 2.5x1020; grows 10 fold every 5 years
World population: 7.4x109
Neurons per human brain: 86x109
- 2013: transistors ever made exceeds total human neurons alive
- 2016: transistors made per year exceeds total human neurons alive
This doesn't consider the enormous speed difference between neurons and transistors, which is a factor of several million.
The IBM spiking neuron inspired TrueNorth chip has 5,400 transistors per real time spiking neuron, so:
- 2032: neuron equivalent transistors ever made exceeds total human neurons alive
- 2035: neuron equivalent transistors per year exceeds total human neurons alive
Another way of looking at things is that in 2014, enough transistors were manufactured to produce artificial spiking neurons equivalent to 540,000 human brains. This could be one powerful superintelligence, or many smaller ones.
This suggests to the extent that there is a hardware underhang, it isn't likely to last much longer.