How many CPU's are working on blockchain now? How much energy is estimated to be consumed? I read an article on coindesk saying it may surpass all other energy consumption by 2020..... seriously?

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    CPUs may be a poor term to use here. Most hashes in the proof of work are now on dedicated kit. Several years ago there was a move from CPUs to GPUs (ie the processors typically found on graphics cards) and now even they are not enough. ASICs (application specific integrated circuits) are now used, and by large farms of machines working together. Dec 21 '17 at 20:15
  • Yeah, thank for that correction. How would you consider a prober way to describe the computer power applied on blockchain?
    – user152037
    Dec 21 '17 at 21:55
  • I suppose "how many processors". A better question might be "how many hashes". The network sets the difficulty such that a new block is created every 10 minutes on average. So from the difficulty you can infer how many hashes are being done by the network. You could then translate that to some kind of "PC CPU equivalent". The PC I'm on now can (in parallel on 8 cores) do roughly 4m SHA256 hashes per second (though the length of the input will vary this). I think each Bitcoin hash is two SHA256 hashes. SHA256d(x) = SHA256(SHA256(x)) Dec 22 '17 at 11:24

I last recently did this calculation: An Antminer S9 uses 1,2kW power, which is 1,2 KiloWattHours (kWh). If we multiply with 24 and with 365 I get around 1000kwh. At Blockchain.info there was end of November 10,445,729,472 GH/s, or 10’445’729 TH/s. Divided by the power of an Antminer S9 with 13 TH/s, I’d need 800’000 Antminer S9. They would consume 10’000 KWh, and if I need 800’000, I get 8’000’000’000 KWh, which is 8’000’000 MWh (Mega Watt hours), is 8’000 GWh (Giga Watt hours). Not all are using S9, so it might be a bit higher...

Compare this to a water cooker, or a hair dryer, which uses 2kw. Instead of making tea, or drying your hairs, consider mining a bit!

In summary this means, on the other side of the power plug must be a power system which can supply ~1000 MegaWatts. This is the range of large industrial systems like carbon or atomic power supplies. Or even better, 500 wind power turbines at 2MW.

I cannot predict the future in 2020, but this would be a bit too much...


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