Author: walter irvin
Date: 08:29:11 10/16/99
Go up one level in this thread
On October 16, 1999 at 10:31:11, Robert Hyatt wrote: >On October 16, 1999 at 08:27:03, Jeremiah Penery wrote: > >>On October 15, 1999 at 23:21:29, Robert Hyatt wrote: >> >>>On October 15, 1999 at 18:29:28, Eelco de Groot wrote: >>> >>>>Finally some real news on this! Thanks Scott! Is it really true that the >>>>original chip didn't use extensions at all in the last 4 ply search, where the >>>>chips were used, does anybody know? I read something like that in a Dutch post >>>>by Vincent on the semi official CSVN mailinglist. >>>> >>>>Regards,Eelco >>> >>> >>>The chess chip didn't do 'singular extensions'. I have not seen anything >>>about whether it used in check extensions or anything else. Had I done the >>>chip I probably would have not done _any_ extensions in the hardware for >>>reasons that are a bit complex to get into here unless someone wants to >>>discuss the issue in more detail. >> >> >>I would be interested in hearing about it (provided it isn't _too_ technical :). >> >>Jeremiah > > >The issue is load-balancing. They do a two-level parallel search. The first >4 plies are searched serially (one cpu). The next 4 are searched in parallel >on the SP cpus. The last 4 are searched in parallel on each SP's 16 chess >processors. If the chess processors do a lot of extensions, then the trees they >search will vary in size too much and make the load balancing issue very >complex. I would do the extensions in the first 2/3 of the search, and then >want the hardware to simply give me a search result in a very predictable amount >of time. No extensions would help that. And if the extensions are done >normally in the first 8 plies, those 8 plies turn into 30+ plies in some >variations anyway... first i'm going to admit that i know as much about multi processing as i do about brain surgery .but it just seems to me that if a person had say 4 cpu's a way to attack the problem COULD be as follows . 1.first divide the moves if there are 20 then each gets 5 ect 2.after each cpu gets to say 5 ply take the high score and go with it .disconect the other 3 cpu's transfer them up the tree to 6 ply do the same thing over and over to get real deep ?????? maybe if you could get deep enough , you could turn tactics into strategy just by sheer depth ???????
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