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
