Author: Robert Hyatt
Date: 07:38:02 10/02/01
Go up one level in this thread
On October 02, 2001 at 04:54:13, Bruce Moreland wrote: >On October 01, 2001 at 00:36:48, Robert Hyatt wrote: > >>On September 30, 2001 at 14:47:21, Bruce Moreland wrote: >> >>>On September 29, 2001 at 14:54:03, Robert Hyatt wrote: >>> >>>>On September 29, 2001 at 10:41:37, Miguel A. Ballicora wrote: >>> >>>>>Super-linear speedups are "probably" impossible but so far I did not see that >>>>>they are "provably" impossible. I would settle with "They are believed to be >>>>>impossible". >>>>> >>>>>Regards, >>>>>Miguel >>>> >>>> >>>>They simply _are_ impossible. Unless you believe in perpetual >>>>motion, infinite compression, a fire that will burn forever, etc. >>> >>>Take a human who can move a 200-pound box, but only by scraping it along the >>>ground. Compute the time it takes him to move 10 such boxes 100 yards. >>> >>>Assume that two humans can move a 200-pound box more easily. Can they move a >>>200-pound box more than twice as fast as one human? Would this violate laws >>>against perpetual motion? Of course not. It is perfectly valid to consider >>>working in parallel rather than working serially. The mechanics of the task >>>might change, resulting in much increased efficiency -- they can lift the box >>>off the ground. >> >> >>I think that after you think about this example, you will see the flaw. >>Lifting the box off the ground takes _more_ effort. So the two people are >>doing _more_ work in a given period of time than two people pushing two boxes >>at the same time. The ancient Egyptions found that dragging was better than >>lifting. :) >> >> >> >>> >>>Two workers cooperating to perform a task, do not *have* to go less than or >>>equal to the speed of two workers, each of whom does exactly half of a task that >>>can be fairly divided in two. >>> >>>There exists the opportunity for synergy. >>> >>>The argument that the above violates the prohibition against perpetual motion is >>>fallacious. >>> >>>bruce >> >> >>Not after you think about it. If two people work and each of them moves 5 >>blocks, then they do no more work than the 1 person did moving 10. But they >>did it in twice the time. If they _lift_ the block _and_ move it, they are >>doing _more_ work per unit of time. They should have moved the blocks >>faster one at a time, but they were taking it easy... >> >> A computer can't do that. > >You can't possibly be arguing that there is nothing that N (N>1) people can't do >in less than 1/N the time that it takes one person. > >I was trying to find an obvious example. If you don't like that one, I'm sure >there is another one. > >bruce If you mean something that takes one person N units of time to do, and two can do it in less than N/2 units of time, then no, I don't believe it is possible. The exception is that I have to move a 400 pound box. I can't move it by myself, probably. So I can't do it at all. Two people can probably shove it around. But I can't think of any thing that one can do, where two can do it twice as fast, assuming that two don't do more physical work than the one person did. Otherwise it isn't reasonable, as it would be like comparing two 1ghz processors to one 800mhz processor. The two 1 gigs should run more than twice as fast. They are doing more than twice as much work. If you can find an example, it would be interesting to analyze it. Either both do more work than one would do, or else there is a trick involved. IE you have to simultaneously nail up both ends of a long board. One person has to walk back and forth multiple times. Two would not. But in that case, the two-person team eliminated work required of the one person team, _before_ the project even starts. I don't see any possible analogy applied to alpha/beta search.
This page took 0.05 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.