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Subject: Re: Results of John Merlino's Chessmaster survey?

Author: John Merlino

Date: 11:10:55 12/03/01

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On December 01, 2001 at 19:23:50, Jason Williamson wrote:

>On November 30, 2001 at 21:18:59, John Merlino wrote:
>
>>On November 30, 2001 at 18:36:58, Jason Williamson wrote:
>>
>>>Surely that time could be improved?  Or is it still memory issues as the major
>>>problem?
>>
>>Definitely memory issues. The import that Chessmaster uses (which, admittedly is
>>quite ancient and nobody really wants to touch it) is rather slow. But the
>>problem is the memory requirements. A lot of time could be spent on optimization
>>and so forth, but it is hard to justify it with regards to the schedule,
>>considering that the feature is probably used by only 0.01% of our users (if
>>that!).
>>
>>During import, each node requires 43 bytes of data. This adds up very quickly
>>when you're talking about 40 moves each of 140,000 games. Worst case scenario
>>(which isn't actually possible, as there have to be SOME repeated moves) would
>>be over 240 million bytes of RAM required.
>>
>>I did spend a fair amount of time (i.e. a couple of days) trying to improve
>>things, and this was the result. The original code (written long before I got on
>>the scene) required 92 bytes of data per node. But it wasn't a problem because
>>the format limited a book to a maximum of 64K moves. So the maximum memory usage
>>for the old format was only about 6MB -- not a big deal.
>>
>>If I felt like spending a couple of weeks, things might be improved noticeably.
>>Unfortunately, I don't feel like it! (and don't have the time even if I did feel
>>like it).
>>
>>Hopefully, the quality of the new book will make it so the opening book editor
>>is used even less!
>>
>>jm
>
>
>Yeah, if the new book is good, there won't really be much need to wreck it with
>random PGN games.  :D  For most engines I use the book it comes with, ie, Fritz
>gets its Fritz book and so on.

Good news. I tried creating the same book as above (from a PGN file of about
141,000 games) using a release build of the next version of Chessmaster. A debug
build (on a PIII-600 with 384MB of RAM) took almost 3 hours. However, a RELEASE
build, on a PIII-600 with only 128MB of RAM, took only 66 minutes!

This is good news....

jm



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