Editing Artificial general intelligence (section)

===Early estimates===
[[File:Estimations of Human Brain Emulation Required Performance.svg|thumb|right|Estimates of how much processing power is needed to emulate a human brain at various levels (from Ray Kurzweil, [[Anders Sandberg]] and [[Nick Bostrom]]), along with the fastest supercomputer from [[TOP500]] mapped by year. Note the logarithmic scale and exponential trendline, which assumes the computational capacity doubles every 1.2 years. Kurzweil believes that mind uploading will be possible at neural simulation, while the Sandberg, Bostrom report is less certain about where [[consciousness]] arises.{{Sfn|Sandberg|Boström|2008}}|upright=2.6]] For low-level brain simulation, a very powerful cluster of computers or GPUs would be required, given the enormous quantity of [[synapses]] within the [[human brain]]. Each of the 10<sup>11</sup> (one hundred billion) [[neurons]] has on average 7,000 synaptic connections (synapses) to other neurons. The brain of a three-year-old child has about 10<sup>15</sup> synapses (1 quadrillion). This number declines with age, stabilizing by adulthood. Estimates vary for an adult, ranging from 10<sup>14</sup> to 5×10<sup>14</sup> synapses (100 to 500 trillion).{{Sfn|Drachman|2005}} An estimate of the brain's processing power, based on a simple switch model for neuron activity, is around 10<sup>14</sup> (100 trillion) synaptic updates per second ([[SUPS]]).{{Sfn|Russell|Norvig|2003}}

In 1997, Kurzweil looked at various estimates for the hardware required to equal the human brain and adopted a figure of 10<sup>16</sup> computations per second (cps).{{Efn|In "Mind Children"{{Sfn|Moravec|1988|page=61}} 10<sup>15</sup> cps is used. More recently, in 1997,{{Sfn|Moravec|1998}} Moravec argued for 10<sup>8</sup> MIPS which would roughly correspond to 10<sup>14</sup> cps. Moravec talks in terms of MIPS, not "cps", which is a non-standard term Kurzweil introduced.}} (For comparison, if a "computation" was equivalent to one "[[FLOPS|floating-point operation]]" – a measure used to rate current [[supercomputer]]s – then 10<sup>16</sup> "computations" would be equivalent to 10 [[Peta-|petaFLOPS]], [[FLOPS#Performance records|achieved in 2011]], while 10<sup>18</sup> was [[Exascale computing|achieved in 2022]].) He used this figure to predict the necessary hardware would be available sometime between 2015 and 2025, if the exponential growth in computer power at the time of writing continued.