Sunday, 18 November 2012

18th November weekly pool statistics

Welcome, miners. 

Something quite strange happened this week. The weekly average network hashrate dropped by almost two Thps. At the same time, the percentage of the network hashrate for each of the top seven pools rose significantly, in some cases reversing longstanding downward trends. The smallest of the top seven, Ozcoin is at ~ 1Thps.

In order for this to occur, some of the network hashrate went offline this week without affecting the larger pools at all, so none of it was from miners at the larger pools. As far as I can tell, the smaller pools that lost hashrate did not lose a total of ~ 2 Thps. So this loss in network hashrate must be from one or more solominers.

My suspicion is that some testing of ASICs has occurred and has now ended. Perhaps it was thought that by gradually adding hashrate no one would notice the increase, but they didn't think about gradually ending testing, hence the rapid decline. And it wouldn't be particularly noticeable if the historic charts of pool % of network hashrate were not available.

Anyone have other ideas?

Feel free to comment. I'll try to reply, but I've just realised there's some problem preventing me from reply at the moment. I hope to get it fixed soon.

Average hashrate:
Average hashrate = Total shares / Total round time

Weekly average round length as a fraction of difficulty:
Average number of shares submitted per round / difficulty

Figure 1: Table of all pools with public data and their various statistics averaged for the last seven days - for smaller pools the average may be more or less than seven days, depending on number of blocks solved for the week.
Figure 2: Chart of network hashrate, hashrate of the largest mining pool, combined hashrates of the three largest mining pools, and a line representing 50% of the network hashrate. Handy if you're worried about 51% attacks.
Figure 3: Chart of chronology of pool hashrates, averaged per week.
Figure 4: Chart of average hashrates per pool per round for the week.
Figure 5: Chart of chronology of negative binomial CDF probability of shares submitted and blocks produced for the week.
Figure 6: Chart of chronology of round length divided by difficulty, averaged per week.
Figure 7: Chart of percentage of orphaned blocks produced by the pool, averaged per week.
Figure 8: Chart of hashrate vs round length for hoppable pools (the larger the hashrate increase at the start of a round, the larger the loss to strategic miners).
Figure 9: Chart of fulltime miner earnings loss at a proportional pool caused by pool hoppers, expressed as expected PPS earnings for fulltime miners. Currently only for Bitlc and Deepbit.

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  1. What about a botnet of some sort as a way to explain the wild hash rate swing? Just throwing out the idea...

    1. I agree. I and some other bitcointalk forum members go into a bit more detail here:

  2. Replies
    1. Colbert, can you post again? I somehow stupidly deleted your post instead of replying to it. :`(


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