I have read a lot of articles about exascale and found out that it may consumes approximately 20MW power envelope. Is it a daily basis or a yearly basis or every second?

Please enlighten me. Here are the papers I have used.


page 1:

One of the main challenges in achieving this goal is power consumption, which a range of HPC system operators have suggested be limited to 20 MW for a full exascale-capable system to mitigate cost of ownership and new power delivery infrastructure costs [2]



page 1

An exascale supercomputer is envisioned to comprise of on the order of 100,000 interconnected servers or nodes in a target power envelope of ∼20MW, with sufficient memory bandwidth to feed the massive compute throughput, sufficient memory capacity to execute meaningful problem sizes, and with user intervention due to hardware or system faults limited to the order of a week or more on average [3].

1 Answer 1


20MW is the total power. Power on the computer for an hour and you've used 20MWh. To calculate the cost, multiply with the cost of electricity, e.g. $0.10/kWh.

Example from Wikipedia:

Tianhe-1A consumes 4.04 megawatts (MW) of electricity. The cost to power and cool the system can be significant, e.g. 4 MW at $0.10/kWh is $400 an hour or about $3.5 million per year.

Edit: To respond to the comment below, Watt is defined as energy (joule) per second. So that should answer your question: 20MW equals 20MJ per second. For each second the supercomputer is powered on, it consumes (up to) 20 megajoule of energy.

  • Are you saying that its an hourly basis? But it's a different supercomputer. Tianhe-1A is not an exascale supercomputer so they may differ in power consumption. Aug 29, 2018 at 13:58
  • I edited my answer. The Tianhe-1A was just an example I took from Wikipedia to show how to calculate the electricity costs per year. No matter whether it's a supercomputer or not, each computer consumes a certain amount of energy (joule) per second, which is called "Watt".
    – Tommiie
    Aug 30, 2018 at 7:10

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