Author: Georg v. Zimmermann
Date: 08:21:02 08/27/02
Go up one level in this thread
On August 27, 2002 at 10:28:09, K. Burcham wrote: > >I am not clear on these questions: > >1. when does a program write to hash? whenever it is playing or analyzing, but not when playing book moves. >2. when does a program write to the hard drive? to save learning data at the end of a game, or when it exits. Some programs write a few lines into a log file. All of this is not time critical. >3. when does a program write to ram separate from the hash? all the time. Remember at every node we are updating the board ! But of course it only writes to the ram allocated to it (unless we have a big bug). >4. If a pc has 512 megs ram, If we set hash at 64 megs, what happens when hash >gets full? Program will start to overwrite its hash table, using more or less clever algorithms to figure out what to keep and what to overwrite. >5. lets say a program stays in book for 15 moves, is the program accessing only >the hard drive to play book moves? Or Is this info moved to ram first and then >the program plays the book from ram? Depends on the program. I would assume that some programs load a small tourney-book into ram and access the rest of the book from HD. But again, this is not time-critical. >6. In the middle game after book, I assume this is when the program starts to >store info from analysis. during this period, what is being read/write to the >hard drive before the hash is full? see above >7. In the middle game after book, what is being read/write to the hard drive >after the hash is full. not more of course. Unless your hash table size is too big. Which is a real BAD idea. Then the computer will start to swap (put some of the hash on the HD). >8. In the middle game after book, if we set the hash at 64 megs, and then this >fills, will the program just use more of the ram, or will it store analysis >directly to the hard drive? Neither. >9. what were programs doing with analysis before hash tables? did all this >analysis set in ram? did the operating system manage this info as needed, and >move the stored analysis to the hard drive as the ram filled? I dont understand that question. hash tables _are_ stored in RAM. And I bet HT have been used from almost the beginning. >10. if we set up two identical computers, running same program on each. >set up same test position on both. computer A with hash tables and computer B >without hash tables. how do these two compare, what memory are they using and >when. > Depending on the program and the position, from factor 2 to factor 100. Average probably between 2.3 and 3.5 > >In other words when exactly, will a hard drive speed increase also speed up a >chess program and why? Only for endgame table bases > >some will say go study on the internet. i have at many sites. i cannot find >answers to these type of questions. if you know a site that answers these >questions, please let me know, i will go there and study. >thanks >kburcham
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