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History of Sia forks

This article describes all forks that Sia went through, planned or unplanned.

2017-12-06 Difficulty adjustment

On December 6th 2017 the Sia chain forked to apply an update to the consensus algorithm. Prior to this update the difficulty changes would be calculated using an overlapping adjustment period, this would cause the difficulty to start oscillating when a sudden change in hash rate happened.

The new algorithm would adjust the difficulty every block based on the timing of all blocks on the blockchain. This ensures that storage contracts will always start and end at the right time, regardless of hash rate changes.

But there was a bug in the new algorithm that caused to difficulty to drop sharply, eventually leading to dozens of blocks being mined per minute. The blocks could not propagate through the network quickly enough for all the pools to catch up, so ended up mining all of them. Then the difficulty quickly rose up again landing on a stable 30 minutes per block rhythm.

2018-01-21 Difficulty correction

Up to this point the blocks were still 30 minutes each. While this is inconvenient for transacting coins it was not a big problem for the network. The block rewards also dropped to 1/3 of what they should be so some miners left. On the 21st of January 2018 the network forked again to correct the algorithm back to 10 minute blocks. After the 21st the difficulty started rising rapidly because that same day Bitmain started sales of their Antminer S3 miners. Because of the huge inflation in hash rates the block times briefly dropped to 10 minutes before the algorithm could adjust enough to reach its desired timing.

Despite the 46 days of 30 minute blocks the network was still ahead of schedule compared to the global average of block times. So the difficulty briefly rose to 30 minutes again to compensate for the inaccuracies of the previous difficulty algorithm.

forks/history_of_sia_forks.1540542329.txt.gz · Last modified: 2018/10/26 08:25 by Fornax