Author: Tom Harding 2015-06-08 00:36:44
Published on: 2015-06-08T00:36:44+00:00
In September 2014, the bitcoin ecosystem began a collective experiment where available block space at times fell short of the space required to mine all transactions that would have been included. Despite the average block being about 400K, real blocks are either bigger or smaller due to factors such as the random length of time between blocks. Transactions were confirmed at a rate of about 100000/day, with the average transaction size for the past 6000 blocks being 545 bytes. Using these values, it was estimated that a maximum-size block would be expected every 1 hour and 44 minutes on average. If the transaction rate doubles, we should expect a maximum-size block every 14 minutes on average, but this estimate is understated due to transaction size and submission rate having their own distributions. These calculations were confirmed by empirical observation of the most recent 6000 blocks. In many cases, miners chose to create a 750KB block, which is unusually likely to be followed by another 750KB or 1MB block because the next interval starts off with a 250KB backlog. Some backlog transactions may experience more than one block delay in these cases. The onset of the some-blocks-at-maximum era can be seen in the chart posted earlier, which shows how often this has happened. The theoretical formula for the time before an inter-block interval of at least a given length is used to obtain minutesBetweenFullBlocks, which was calculated to be 104. This non-linearity makes sense because doubling the average without raising the maximum requires disproportionately more maximum-size blocks. The chicken-crossing-the-road problem was used in the calculation of wait time, and there is some discussion of it at https://github.com/nanotube/supybot-bitcoin-marketmonitor/pull/68.
Updated on: 2023-06-09T22:37:35.410679+00:00