Author: Vincent Diepeveen
Date: 10:23:32 09/18/01
Go up one level in this thread
On September 18, 2001 at 12:24:26, Robert Hyatt wrote: >On September 18, 2001 at 11:50:40, Vincent Diepeveen wrote: > >>On September 18, 2001 at 11:31:00, Robert Hyatt wrote: >> >>>On September 18, 2001 at 09:10:02, Vincent Diepeveen wrote: >>> >>>>On September 17, 2001 at 12:00:45, Gian-Carlo Pascutto wrote: >>>> >>>>Hello now that i saw this link and downloaded the source i >>>>realized this was also published in advances in ICCA volume 8, >>>>of course i got this book and first removed some dust from it, >>>>after which i opened it and saw at page 71 claimed next >>>>by M. Brockington and J. Schaeffer >>>> >>>>"... Although most parallel alfabeta-programs take months to develop, >>>>the game-independant library allows users to integrate parallellism >>>>into their application with only a few hours of work" >>>> >>>>[cough] >>>> >>>>Well if no one here manages to do that, who am i to say that the >>>>remainder of this algorithm is worth trying? >>>> >>>>For sure there is a speedup problem. >>>> >>>>But there is more. It's a complete different algorithm than YBW. >>>> >>>>Which means that APHID already says who has to search what before relevance >>>>of parallel splitting has been indicated. Considering that nowadays we >>>>use nullmove bigtime, this makes APHID completely outdated, because >>>>it in short doesn't wait at all! >>> >>> >>>You need to _read_ the article first. That version of Crafty used null-move >>>R=2, recursively. Changing to R=2-3 would be a trivial change. >> >>Bob the speedups claimed are for serach depth from 5 ply to 8 ply MAXIMUM. >> >>Based entirely upon a program called >> >>> >>>> >>>>First few pages it says that a major problem with YBW is the idle time. >>>> >>>>This refers to the fact that YBW for each node needs a result for the >>>>first move first before splitting other moves. Now this is of course very >>>>true, but this directly also shows that APHIDs branching factor is by >>>>definition bigger than algorithms which use YBW. >> >>>this is incorrect. Cray Blitz didn't use YBW either. It tried to do that >>>whenever possible, but it _never_ waited, _ever_. It would choose to split >> >>I'm doing that partly too, but i directly resplit if possible then, so i see >>DIEP like a program which splitting strategy is completely YBW dominated. >> >>Did you resplit in Cray Blitz when possible? > > >yes I did... > > >> >>>_somewhere_ rather than sitting idle, taking a chance that the parallel work >>>done was needed. >> >>>>Back in 1996 for example TheTurk which used APHID searched 2500 nodes >>>>a second. I don't need to mention that for nowadays networks capable >>>>of searching millions of nodes a second, that branching factor is a bigger >>>>problem than it used to be in 1997. >>>> >>>>Note that Deep Blue used seemingly a similar approach to APHID, which >>>>considering its search depth was no problem to use of course. >>> >>> >>> >>>Deep Blue's search was not related to the APHID approach in any fashion. Their >>>search was completely different for obvious hardware reasons. >> >>The explanation given by Hsu in IEEE99 is pretty similar to the story >>the APHID guys give... > >I don't see how. Hsu's algorithm is two-level. Aphid is not. in ICCA8 it is even 3 level if we can talk about levels anyway. > >> >>> >>>> >>>>>On September 17, 2001 at 11:54:35, Vincent Diepeveen wrote: >>>>>>On September 17, 2001 at 07:10:46, Gian-Carlo Pascutto wrote: >>>>>> >>>>>>Well show me the code and i can run it here at my 100mbit >>>>>>network then! >>>>> >>>>>ftp://ftp.cs.ualberta.ca/pub/games/aphid >>>>> >>>>>APHID libs, crafty version for them >>>>> >>>>>You need PVM (Parallel Virtual Machine, standard message-passing >>>>>lib), and probably a quick look at some of their docs how >>>>>to set up the config files. >>>>> >>>>>You can get the papers/thesis and all from >>>>> >>>>>http://www.cs.ualberta.ca/~games/aphid/index.html >>>>> >>>>>-- >>>>>GCP
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