Author: Uri Blass
Date: 00:39:13 04/04/02
Go up one level in this thread
On April 03, 2002 at 20:22:02, Vincent Diepeveen wrote: >On April 03, 2002 at 15:00:05, Uri Blass wrote: > >I do not agree. 2 processors is for free getting nearly 2 times >faster. > >If that requires effort, it is a peanut compared to the effort >of writing a very efficient search. > >If you have a very efficient search, then again the argument is >even harder: getting nearly 2 times faster is making your thing >2 times faster than the opponent. > >This removes simply disadvantages as being a slow searcher >(in my case). I'm always faster than the guys who do not manage >to get dual CPU. > >then let's talk about price. the fastest single cpu liquid cooled CPU >is always slower for DIEP than DIEP at a dual CPU, whereas everyone >understands that liquid cooled VAPOCHILL a look like stuff and the >latest CPU is nearly impossible to get for me. Not to mention >unaffordable (also hard to get is a chip that is fast AND overclocks well). > >In short being SMP removes always the 'i need to invest just too much >money for this world champ' argument. > >If i show up tournaments with a dual 1.2Ghz K7 (which is pretty likely), >then i could perhaps for the world champs upgrade it pretty cheap to 1.5Ghz >dual K7 (above those speeds i already tried, the power supply doesn't >give enough power for speeds above 1.5Ghz so i would need more money then >to buy an expensive and better E-ATX PSU). > >Anyhow. Easier is just put in 1.4MPs pretty cheap upgrade. i'm nearly 3Ghz >then (when talking about K7). a dual 1.4Ghz K7 is the same speed for DIEP >like a P4 at about 6Ghz. > >So whatever you put single cpu against me, i'm faster simply. All those >thousands of dollars you can invest for latest cpu. If you are dual >you CAN be fast for little money (doesn't take away that usually >you then also invest for expensive CPU's to be even faster, but >that's other thing). > >We all know how hard it is nowadays to improve search. It is nearly >impossible with a search to beat nullmove + efficient qsearch + nullwindow >search (PVS). > >Of course you can shout about forward pruning, but before you get that >to work you are 8 years further. Even then it is always doubtful it >works at tournament level (considering you already get like 12 ply >easily with just nullmove + well written qsearch). > >So let's assume that someone has put 8 years of his time in improving >search, in fact most time is dedicated by most programmers in >search improvements (amazingly i have to admit that even in DIEP >half of my time still goes to search experiments). > >Suppose that someone manages to get a 5% node improvement by some kind >of search improvement. He earns a nobel prize of course then if it is >lossless (lossy is pretty risky and needs years of testing before it >can be aproved working for him). > >Now compare that with the Huber algorithm which every good programmer >who has a chessprogram can implement within a few days of his time. >Another week debugging and he'll get easily a 1.6 speedup. > >How can you *ever* say that improving the search of the engine >is smarter to do, considering that most programmers i know are >basically busy with search and NOT other things. > >for an investment of at most 2 weeks and new hardware, you get nearly >2 times faster. I don't know a single thing that can speed you up >that much! > >Of course you can go shout about hashtables and nullmove and pondering >in the time of the opponents, but it is >pretty idiotic to assume that someone doesn't use these known things. There are a lot of engines that do not use at least one of these things. My engine does not use null move, hash tables or pondering and has almost no evaluation and no book and has almost no knowledge in the evaluation(for example it's knowledge about pawn structure is only to punish pawns on the same file and it knows nothing about weak pawns or passed pawns). Inspite of these problems it could draw 3-3 with another new Israeli engine(Genesis) when Genesis is using null move and hash tables. See http://f11.parsimony.net/forum16635/messages/24414.htm for the games. I believe that the search rules can be improved significantly without null move or hash tables. Uri
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