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Title: can network speed be directly derived from difficulty? Post by: satonit on May 25, 2011, 09:37:08 PM say.. average a miner can get 1.8 ghash per KWH.
if difficulty is at 420,000 ... can i derive ghash of ENTIRE network some how?? bitcoinchart say 3,500,000 mhash... how they calculate? 1 difficulty = 8 mhash? also, what EXACTLY is a bitcoin "hash" ? 1 "hash" is actually 2 x AEC256 ? Title: Re: can network speed be directly derived from difficulty? Post by: Stephen Gornick on May 25, 2011, 09:42:23 PM if difficulty is at 420,000 ... can i derive ghash of ENTIRE network some how?? Quote So total network power, in hash/sec, is then - http://forum.bitcoin.org/?topic=402.msg10162#msg10162 (http://forum.bitcoin.org/?topic=402.msg10162#msg10162)(difficulty * 2^32) / 600 Where 600 is a smoothed approximation of last-block-interval-in-seconds. An estimate of the current Network Hashrate is available from: - http://bitcoinwatch.com (http://bitcoinwatch.com) Graphs of these levels are here: - http://bitcoin.sipa.be (http://bitcoin.sipa.be) Title: Re: can network speed be directly derived from difficulty? Post by: Pieter Wuille on May 25, 2011, 09:43:02 PM 1 "hash" is double-SHA256 applied to a block header. Because some parts can be pre-calculated, and some parts ignored for our application, it is in reality equivalent to processing approximately 1.9 SHA256 blocks.
There is an easy relation between difficulty and block rate. For each block the network finds, on average 2^48/65535 (=4295032833) times the difficulty hashes have been performed. There is a relation between the difficulty and the network hash rate as well, assuming you know how often a block is found. Assuming there is one block every 10 minutes (as the network aims for), there are difficulty*2^48/65535/600 hashes done per second (=7158388*difficulty). If there are more blocks found than 1 per ten minutes, the rate is proportionally higher. Currently (at difficulty 244139), this means that each block requires on average a whopping 1048587089228612 hashes to be performed. |