Update released December 27

[Chris Sokolowski]

Today we released a minor change to the mining server. Previously, when the mining server decided on how many miners to assign to mine each coin, the mining server considered the average block time of the last 100 blocks. Today, we discovered that this implementation has an unintended side-effect.

For coins that ocsillate between two states - a low profitability with long block times and a high profitability with short block times - the average block time is not useful because it represents neither case. When the short block times occur, the mining server will assign too many miners to the coin since it expects the coin to have the much longer average block time. The miners will then compete with each other to submit blocks and will experience more orphans and work restarts than necessary.

We changed the mining server to use the median block time of the past 100 blocks instead of the average. The result of this change will be that fewer miners will be assigned to coins that have oscillating block times. This change will slightly decrease reported profitability per MH/s, but since it will reduce the amount of time spent in work restarts (thus increasing the hashrate), the overall effect will be increased earnings for miners.

We are currently working on another change, which will be released in the next week. This change will improve how the mining server chooses to assign miners to coins by calculating each miner's theoretical hashrate that would occur if there never was a work restart. The current implementation is not advanced enough to consider that hashrate declines when there are many coin switches and therefore slightly overallocates hashpower to coins with frequent blocks. We will provide more information when this update is ready.