Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.stack.nl!aioe.org!.POSTED!not-for-mail From: "Rod Pemberton" Newsgroups: comp.lang.forth Subject: Re: Green Array energy consumption: a reality check. Date: Mon, 20 Jan 2014 16:34:33 -0500 Organization: Aioe.org NNTP Server Lines: 47 Message-ID: References: <52d2b239$0$25047$e4fe514c@dreader37.news.xs4all.nl> <52d3dce6$0$25062$e4fe514c@dreader37.news.xs4all.nl> <52dc29b2$0$24920$e4fe514c@dreader36.news.xs4all.nl> <78b7563a-6442-4908-b547-eb6ea6cd3c88@googlegroups.com> NNTP-Posting-Host: CNsg4fVcCsvs3UaOgZtQCw.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Opera Mail/12.16 (Linux) X-Notice: Filtered by postfilter v. 0.8.2 Xref: csiph.com comp.lang.forth:27981 On Mon, 20 Jan 2014 15:55:42 -0500, wrote: > On Sunday, January 19, 2014 11:50:18 PM UTC+1, Rod Pemberton wrote: >> On Sun, 19 Jan 2014 16:40:07 -0500, wrote: >> > Well actually, as you alluded in your first post, it's not so much a >> > matter of speed as of energy consumption. >> >> Bitcoins are first come. I.e., whomever solves a "proof of work" >> problem first, gets the coins for it. So, I'd say speed is very >> important... > > I think that's actually not true, since the proof of work problem > involves brute-forcing a hash function and not some sequential > algorithm. I think speed of a single hash computation doesn't matter, as > long as it stays considerably shorter than the average block > confirmation time on the bitcoin network (calibrated to be 10 minutes). > > Suppose I have two machines at my disposal. The first consumes an energy > E1 to produce 10^6 hashes in time T1; the second takes energy E2 < E1 to > produce the same amount of hashes in time T2 > T1. > AIUI, you don't get to choose who your competition is. Multiple computers, or groups of them, attempt to solve the exact same proof-of-work at the same time. I.e., if this was a foot race, it's a sprint with many losers and one winner. If my machines are attempting to solve the same proof-of-work as your machines, and my machines solve it first, you don't get any bitcoins. I get the bitcoins. Once a proof-of-work has been solved, any computers that were attempting to solve that proof of work but failed stop working that proof and start another. Now, if your is working a different proof than my machine, you might have a chance at earning some coin. But, if my faster machine is competing against your slower machine, you lose again, and again, ... Does it matter to me how much energy I consume? Yes, but only once my machines are sufficiently faster than yours so I earn the bitcoin. If I'm not earning *any* bitcoin because my machines are too slow, it doesn't really matter whether I have an energy efficient machine or not. I'm not receiving any coinage. All my machines are a loss. So, AIUI, speed matters very much. Rod Pemberton