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Glaurung 2 - epsilon/3

PostPosted: 07 Jun 2007, 22:44
by Tord Romstad
Glaurung 2 - ε/3, the latest development version of the program which will eventually be released as Glaurung 2, is now ready for download from my web site. At the moment, only the source code and executables for Mac OS X and Linux are included. 32-bit and 64-bit Windows executables will follow soon. The most important new feature is the addition of parallel search: Glaurung can now use up to 4 CPUs (or so I hope; I haven't tested it with more than 2).

On single-CPU computers, there is no significant difference between Glaurung 2 - ε/2 and Glaurung 2 - ε/3. There are a few very minor bug fixes and optimizations, but nothing which is likely to have a measurable impact on playing strength. I therefore advice those of you who spend lots of effort on making rating lists and have already started testing 2 - ε/2 to skip the new version, or to let it replace the old version and inherit its rating.

In more detail, the changes in this new version are (taken from the README file):
  • Parallel search, with support for 1-4 CPUs. The program currently always allocates a separate pawn hash table and material hash table for four threads, which is a pure waste of RAM if your computer has just a single CPU. This will be fixed in a future version.
  • Fixed a bug in book randomization. When using Polyglot books, the previous version would always select exactly the same move in the same position after a restart of the program. Thanks to Pavel Háse for pointing this out.
  • Fixed a UCI pondering bug: Glaurung no longer instantly prints its best move when the maximum depth is reached during a ponder search, as the previous version did. According to the UCI protocol, it is not allowed to print the best move before the engine has received the "stop" or "quit" command.
  • Additional search information: The new version displays hash saturation and the current line(s) of search.
  • Several minor bug fixes and optimizations in the search and evaluation.

Glaurung 2 - ε/3 is probably the version that will play in the OPCCC in the end of the month.

Tord

Re: Glaurung 2 - epsilon/3

PostPosted: 08 Jun 2007, 08:04
by Pradu
Great! How about entering it in the ACCA tournament as well? :mrgreen:

Re: Glaurung 2 - epsilon/3

PostPosted: 08 Jun 2007, 08:45
by Tord Romstad
Pradu wrote:Great! How about entering it in the ACCA tournament as well? :mrgreen:

I am not a big fan of on-line tournaments, particularly not in the middle of summer, but it could still happen. I will probably not decide whether I will participate before the tournament is close enough that I can find a reliable weather forecast for the weekend. It is not tempting to spend a nice, sunny weekend sitting at home in front of the computer.

Entering with an operator is of course possible, but would perhaps make the tournament less attractive for other participants.

Tord