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I've been watching the global estimated hash-rate, as estimated by blockchain.info.
While it is clearly increasing, it also varies around 20% day-to-day.
Yesterday, it was around 4,325,000 TH/s.
Today, it is 5,688,000 TH/s.
Wouldn't miners want to keep their equipment running 24/7?
That is a lot of hashing-power to go on and offline so frequently. What is causing this?
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The actual hash rate of the network is not (and likely cannot be) known. Blockchain.info and any other website that tells you the network hashrate is extrapolating it from the frequency that blocks are being produced and the difficulty of each block. However, because there can be significant variance in the times between blocks, this can sometimes make it seem like the hashrate is significantly higher or lower than it actually is. This is likely what causes the variation that you see in blockchain.info's chart.
Around 144 blocks are produced every day, so block time volatility hardly explains daily averaged hash rate deviations of almost 40%. – fnieto - Fernando Nieto – 2018-05-18T10:07:50.960
1The block time volatility is literally the only reason for the hash rate deviations because that is the only way for people to measure the hashrate. There is no other way because the hashrate is not directly measurable. – Andrew Chow – 2018-05-18T16:00:22.220
If block time is an average of ten minutes, that means that it is standard between one second and twenty minutes to find the next block but, could be longer on occasion. – Willtech – 2018-05-18T18:59:22.177
The values showed in blockchain.info use the average block times for the 144 blocks in a day. Even if block time variance is high, daily average curve should be smooth in the absence of real hash rate volatility. – fnieto - Fernando Nieto – 2018-05-18T20:51:43.157
The number of blocks per day is not guaranteed to be 144. That is only the average number of blocks per day. Blockchain.info is comparing the number of blocks found per day to the expected number (144) of blocks per day. Block time variance means that not every day will have the same number of blocks. If one day has 6 blocks more (or less) than the previous day, that difference is enough for a 1 exahash/s hashrate difference in the calculation which is noticeable on blockchain.info's graph. Such a variation is not uncommon and averaging does not smooth that out. – Andrew Chow – 2018-05-18T22:06:42.060
3The actual hash rate isn't publicly known. Blockchain.info is probably extrapolating it from some other information (difficulty level, block times, etc) and this jitter could be an artifact of that. They don't seem to explain their methodology so it is hard to know. If this variation is real and not just an artifact, one possible explanation would be variation in the cost of electricity. In some places, electricity is substantially cheaper at night (when overall demand is lower). Or in the other direction, some miners might be using solar power. – Nate Eldredge – 2017-06-05T13:06:07.123
By the way, your link is missing. – Nate Eldredge – 2017-06-05T13:06:54.580