Author: Robert Hyatt
Date: 11:21:41 08/27/01
Go up one level in this thread
On August 27, 2001 at 13:47:27, Tom Kerrigan wrote: >On August 27, 2001 at 13:35:13, Robert Hyatt wrote: > >>On August 27, 2001 at 08:59:00, Robert Hyatt wrote: >> >>>On August 27, 2001 at 04:14:33, Tom Kerrigan wrote: >>> >>>>There are some issues here that have not received due attention. >>>> >>>>First, [as most of you already know,] part of DB's search algorithms and all of >>>>DB's evaluation function algorithms were implemented in custom VLSI chips. This >>>>made it phenominally fast and also means that it can't exist as a PC program >>>>(because you don't have the chips). However, PCs have general purpose >>>>processors, which means they can run any algorithm you can think of, so the idea >>>>of running DB on a PC isn't quite as stupid as most people seem to think, if >>>>you're talking about the algorithms. There are two issues at play when >>>>discussing implementing DB as PC software: >>>> >>>>1) Work involved. Speaking from experience, the time-consuming part of writing >>>>an evaluation function is not the actual coding, but instead deciding which >>>>terms to include and what their weights should be. If you already know _exactly_ >>>>what an evaluation function is supposed to do, (and the DB team does,) I bet >>>>implementing even the most complicated one would only take a couple of weeks. >> >>I missed that statement first time around, until someone sent me email. I >>don't know what kind of evaluation _you_ have written. But _mine_ was not a >>two week implementation project. None of mine have been two week projects. > >Sounds like you're accounting for development time. Are you saying that, given a >list of Crafty's evaluation terms and their weights, you could not reproduce the >function in two weeks? I bet I could. I would have no chance, no. Just the code to recognize blocked pawns, levers, and majorities would take me half of that time to re-do. And if I was doing this, I would assume it was because a new "framework" of a program was done, which would mean old approaches would no longer work. And eval development requires Make/UnMake development as well for the incremental things that are needed. > >>You are behind times. First, ASICS don't cost "millions of dollars". Just read >>some of Hsu's old papers. The first run of the Deep Thought chips cost them >>a couple of thousand dollars, total. And second, it didn't take "years". > >Well, duh. Weren't they using some 4 micron student process? That's worse than >apples and oranges. > MOSIS wasn't a "student process". In 1986 when they did the first batch, 4micron was probably 'current'. And that is _still_ the beauty of ASICS today. They are not ridiculously expensive as designing/fabbing a new CPU turns out to be. >>After >>the first Kasparov match, Hsu took time off, then completely re-designed the >>chips to create the DB2 version, had the chips fabbed, and had everything >>working for the match one year later. Design, implementation, fab, testing, >>assembly, tuning, all in under one year. With all the design and testing done >>by one person. > >Okay, so me saying "months" was accurate. And are you trying to imply that one >year of work is trivial? That Hsu would spend an entire year blindly >implementing algorithms that he jus' figgered were good? That's what he said, yes. And he didn't spend a year, as I mentioned. There was only one year between matches. They didn't decide to go for a re-design until at least 3 months after the first match. He had to convince the rest of the team that the effort was worth it. They all agreed, eventually, that the evaluation definitely need "more stuff". He even designed in a transposition probe into the hardware. But he didn't have time to design the multi-ported memory for it to use. He showed little concern for "what can it do" and instead, seemed to focus on "what _should_ it do?" And he didn't have time to use everything he included, which was pretty interesting information. > >-Tom
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