Published 26 July, 2015; last updated 28 September, 2017

Computing hardware which is equivalent to the brain –

• in terms of FLOPS probably costs between $1 x 10⁵ and $3 x 10¹⁶, or $2/hour-$700bn/hour.
• in terms of TEPS probably costs $200M – $7B, or or $4,700 – $170,000/hour (including energy costs in the hourly rate).
• in terms of secondary memory probably costs $300-3,000, or $0.007-$0.07/hour.

Main articles: Brain performance in FLOPS, Current FLOPS prices, Trends in the costs of computing

FLoating-point Operations Per Second (FLOPS) is a measure of computer performance that emphasizes computing capacity. The human brain is estimated to perform between 10^13.5 and 10²⁵ FLOPS. Hardware currently costs around $3 x 10^-9/FLOPS, or $7 x 10^-14/FLOPShour. This makes the current price of hardware which has equivalent computing capacity to the human brain between $1 x 10⁵ and $3 x 10¹⁶, or $2/hour-$700bn/hour if hardware is used for five years.

The price of FLOPS has probably decreased by a factor of ten roughly every four years in the last quarter of a century.

Main articles: Brain performance in TEPS, The cost of TEPS 

Traversed Edges Per Second (TEPS) is a measure of computer performance that emphasizes communication capacity. The human brain is estimated to perform at 0.18 – 6.4 x 10⁵ GTEPS. Communication capacity costs around $11,000/GTEP or $0.26/GTEPShour in 2015, when amortized over five years and combined with energy costs. This makes the current price of hardware which has equivalent communication capacity to the human brain around $200M – $7B in total, or $4,700 – $170,000/hour including energy costs.

We estimate that the price of TEPS falls by a factor of ten every four years, based the relationship between TEPS and FLOPS.

Main articles: Information storage in the brain, Costs of information storage, Costs of human-level information storage

Computer memory comes in primary and secondary forms. Primary memory (e.g. RAM) is intended to be accessed frequently, while secondary memory is slower to access but has higher capacity. Here we estimate the secondary memory requirements ofthe brain. The human brain is estimated to store around 10-100TB of data. Secondary storage costs around $30/TB in 2015. This means it costs $300-3,000 for enough storage to store the contents of a human brain, or $0.007-$0.07/hour if hardware is used for five years.

In the long run the price of secondary memory has declined by an order of magnitude roughly every 4.6 years. However the rate has declined so much that prices haven’t substantially dropped since 2011 (in 2015).

Calculating the total cost of hardware that is relevantly equivalent to the brain is not as simple as adding the partial costs as listed. FLOPS and TEPS are measures of different capabilities of the same hardware, so if you pay for TEPS at the aforementioned prices, you will also receive FLOPS.

The above list is also not exhaustive: there may be substantial hardware costs that we haven’t included.