By Katja Grace, 7 May 2015 How large does a computer need to be before it is ‘as powerful’ as the human brain? This is a difficult question, which people have answered before, with much uncertainty. We have
Traversed Edges Per Second (TEPS) is a benchmark for measuring a computer’s ability to communicate information internally. Given several assumptions, we can also estimate the human brain’s communication performance in terms of TEPS, and use this
The presence of glial cells may increase the capacity for signaling in the brain by a small factor, but is unlikely to qualitatively change the nature or extent of signaling in the brain. Contents SupportNumber
The brain has about 10¹¹ neurons and 1.8-3.2 x 10¹⁴ synapses. These probably account for the majority of computationally interesting behavior. Contents SupportNumber of neurons in the brainNumber of synapses in the brainNumber of synapses in the neocortexNumber of synapses
Our best guess is that an average neuron in the human brain transmits a spike about 0.1-2 times per second. Contents SupportBias from neurons with sparse activityAssorted estimatesInformal estimatesEstimates of rate of firing in human neocortexEstimates of rate
Cortical neurons are estimated to spike around 0.16 times per second, based on the amount of energy consumed by the human neocortex. They seem unlikely to spike much more than once per second on average, based on this
By Katja Grace, 4 April 2015 Computer hardware has been getting cheap now for about seventy five years. Relatedly, large computing projects can afford to be increasingly large. If you think the human brain is something like
In November 2017, we estimate the price for one GFLOPS to be between $0.03 and $3 for single or double precision performance, using GPUs (therefore excluding some applications). Amortized over three years, this is $1.1
A billion Traversed Edges Per Second (a GTEPS) can be bought for around $0.26/hour via a powerful supercomputer, including hardware and energy costs only. We do not know if GTEPS can be bought more cheaply elsewhere. We estimate that
The Singularity Isn’t Near is an article in MIT Technology Review by Paul Allen which argues that a singularity brought about by super-human-level AI will not arrive by 2045 (as is predicted by Kurzweil). The summarized argument