Author: Tom Kerrigan
Date: 11:53:10 08/27/01
Go up one level in this thread
On August 27, 2001 at 14:21:41, Robert Hyatt wrote: >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, Differing opinions. You (or at least I) can write a _lot_ of code in 80 hours if I already know _exactly_ what it's supposed to do. (Notice that I'm not talking about perfectly optimized code, which wouldn't be necessary. No amount of stupidity could get an evaluation function down to 200 NPS on today's PCs, which is what you get with your made-up 1Mx slower figure.) >>>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. If I were talking about a new CPU, I would have said billions of dollars. Big difference. It does cost hundreds of thousands of dollars per spin to create an ASIC with a reasonably modern process, and doing multiple spins is not out of the ordinary. (Just read any interview with a graphics chip designer.) As for feature size, 4 micron was current in the 70s, not the lateish 80s. And where did Hsu fab the chip? I thought one of the amazing qualities of Hsu's design supposedly was that he got it all to fit on one chip using a completely out-of-date process. >>>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 So he freely admits that he spent significant effort and money (not even his own money, either) implementing algorithms that he didn't even pretend to test or even experiment with? Unless you're just making this up, my opinion of the project is now way lower. -Tom
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