X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=Readme.md;h=e60ac7185d7532a278e2b7856fe6e62cf6825fe6;hp=a68ef560b99f25a05bdca551eee76c6b2a896bc7;hb=bf5ce1c214f8f8e3f98e5e3ac43db0dd28617e35;hpb=800031c94c655e64e436846911e599de6eb35a72 diff --git a/Readme.md b/Readme.md index a68ef560..e60ac718 100644 --- a/Readme.md +++ b/Readme.md @@ -1,7 +1,7 @@ ## Overview [![Build Status](https://travis-ci.org/official-stockfish/Stockfish.svg?branch=master)](https://travis-ci.org/official-stockfish/Stockfish) -[![Build Status](https://ci.appveyor.com/api/projects/status/github/official-stockfish/Stockfish?svg=true)](https://ci.appveyor.com/project/mcostalba/stockfish) +[![Build Status](https://ci.appveyor.com/api/projects/status/github/official-stockfish/Stockfish?branch=master&svg=true)](https://ci.appveyor.com/project/mcostalba/stockfish/branch/master) [Stockfish](https://stockfishchess.org) is a free, powerful UCI chess engine derived from Glaurung 2.1. It is not a complete chess program and requires a @@ -34,15 +34,15 @@ Currently, Stockfish has the following UCI options: A positive value for contempt favors middle game positions and avoids draws. * #### Analysis Contempt - By default, contempt is set to prefer the side to move. Set this option to "White" + By default, contempt is set to prefer the side to move. Set this option to "White" or "Black" to analyse with contempt for that side, or "Off" to disable contempt. * #### Threads - The number of CPU threads used for searching a position. For best performance, set + The number of CPU threads used for searching a position. For best performance, set this equal to the number of CPU cores available. * #### Hash - The size of the hash table in MB. + The size of the hash table in MB. It is recommended to set Hash after setting Threads. * #### Clear Hash Clear the hash table. @@ -55,21 +55,35 @@ Currently, Stockfish has the following UCI options: Leave at 1 for best performance. * #### Skill Level - Lower the Skill Level in order to make Stockfish play weaker. + Lower the Skill Level in order to make Stockfish play weaker (see also UCI_LimitStrength). + Internally, MultiPV is enabled, and with a certain probability depending on the Skill Level a + weaker move will be played. + + * #### UCI_LimitStrength + Enable weaker play aiming for an Elo rating as set by UCI_Elo. This option overrides Skill Level. + + * #### UCI_Elo + If enabled by UCI_LimitStrength, aim for an engine strength of the given Elo. + This Elo rating has been calibrated at a time control of 60s+0.6s and anchored to CCRL 40/4. + + * #### UCI_ShowWDL + If enabled, show approximate WDL statistics as part of the engine output. + These WDL numbers model expected game outcomes for a given evaluation and + game ply for engine self-play at fishtest LTC conditions (60+0.6s per game). * #### Move Overhead - Assume a time delay of x ms due to network and GUI overheads. This is useful to + Assume a time delay of x ms due to network and GUI overheads. This is useful to avoid losses on time in those cases. * #### Minimum Thinking Time - Search for at least x ms per move. + Search for at least x ms per move. * #### Slow Mover - Lower values will make Stockfish take less time in games, higher values will + Lower values will make Stockfish take less time in games, higher values will make it think longer. * #### nodestime - Tells the engine to use nodes searched instead of wall time to account for + Tells the engine to use nodes searched instead of wall time to account for elapsed time. Useful for engine testing. * #### UCI_Chess960 @@ -79,14 +93,16 @@ Currently, Stockfish has the following UCI options: An option handled by your GUI. * #### SyzygyPath - Path to the folders/directories storing the Syzygy tablebase files. Multiple - directories are to be separated by ";" on Windows and by ":" on Unix-based + Path to the folders/directories storing the Syzygy tablebase files. Multiple + directories are to be separated by ";" on Windows and by ":" on Unix-based operating systems. Do not use spaces around the ";" or ":". - + Example: `C:\tablebases\wdl345;C:\tablebases\wdl6;D:\tablebases\dtz345;D:\tablebases\dtz6` - - It is recommended to store .rtbw files on an SSD. There is no loss in storing - the .rtbz files on a regular HD. + + It is recommended to store .rtbw files on an SSD. There is no loss in storing + the .rtbz files on a regular HD. It is recommended to verify all md5 checksums + of the downloaded tablebase files (`md5sum -c checksum.md5`) as corruption will + lead to engine crashes. * #### SyzygyProbeDepth Minimum remaining search depth for which a position is probed. Set this option @@ -127,21 +143,59 @@ more compact than Nalimov tablebases, while still storing all information needed for optimal play and in addition being able to take into account the 50-move rule. +## Large Pages + +Stockfish supports large pages on Linux and Windows. Large pages make +the hash access more efficient, improving the engine speed, especially +on large hash sizes. Typical increases are 5..10% in terms of nps, but +speed increases up to 30% have been measured. The support is +automatic. Stockfish attempts to use large pages when available and +will fall back to regular memory allocation when this is not the case. + +### Support on Linux + +Large page support on Linux is obtained by the Linux kernel +transparent huge pages functionality. Typically, transparent huge pages +are already enabled and no configuration is needed. + +### Support on Windows + +The use of large pages requires "Lock Pages in Memory" privilege. See +[Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows) +on how to enable this privilege. Logout/login may be needed +afterwards. Due to memory fragmentation, it may not always be +possible to allocate large pages even when enabled. A reboot +might alleviate this problem. To determine whether large pages +are in use, see the engine log. ## Compiling Stockfish yourself from the sources -On Unix-like systems, it should be possible to compile Stockfish -directly from the source code with the included Makefile. +Stockfish has support for 32 or 64-bit CPUs, certain hardware +instructions, big-endian machines such as Power PC, and other platforms. + +On Unix-like systems, it should be easy to compile Stockfish +directly from the source code with the included Makefile in the folder +`src`. In general it is recommended to run `make help` to see a list of make +targets with corresponding descriptions. + +``` + cd src + make help + make build ARCH=x86-64-modern +``` -Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT -instruction, big-endian machines such as Power PC, and other platforms. +When not using the Makefile to compile (for instance with Microsoft MSVC) you +need to manually set/unset some switches in the compiler command line; see +file *types.h* for a quick reference. -In general it is recommended to run `make help` to see a list of make -targets with corresponding descriptions. When not using the Makefile to -compile (for instance with Microsoft MSVC) you need to manually -set/unset some switches in the compiler command line; see file *types.h* -for a quick reference. +When reporting an issue or a bug, please tell us which version and +compiler you used to create your executable. These informations can +be found by typing the following commands in a console: +``` + ./stockfish + compiler +``` ## Understanding the code base and participating in the project @@ -151,12 +205,12 @@ community effort. There are a few ways to help contribute to its growth. ### Donating hardware Improving Stockfish requires a massive amount of testing. You can donate -your hardware resources by installing the [Fishtest Worker](https://github.com/glinscott/fishtest/wiki/Running-the-worker) -and view the current tests on [Fishtest](http://tests.stockfishchess.org/tests). +your hardware resources by installing the [Fishtest Worker](https://github.com/glinscott/fishtest/wiki/Running-the-worker:-overview) +and view the current tests on [Fishtest](https://tests.stockfishchess.org/tests). ### Improving the code -If you want to help improve the code, there are several valuable ressources: +If you want to help improve the code, there are several valuable resources: * [In this wiki,](https://www.chessprogramming.org) many techniques used in Stockfish are explained with a lot of background information. @@ -167,8 +221,8 @@ generic rather than being focused on Stockfish's precise implementation. Nevertheless, a helpful resource. * The latest source can always be found on [GitHub](https://github.com/official-stockfish/Stockfish). -Discussions about Stockfish take place in the [FishCooking](https://groups.google.com/forum/#!forum/fishcooking) -group and engine testing is done on [Fishtest](http://tests.stockfishchess.org/tests). +Discussions about Stockfish take place in the [FishCooking](https://groups.google.com/forum/#!forum/fishcooking) +group and engine testing is done on [Fishtest](https://tests.stockfishchess.org/tests). If you want to help improve Stockfish, please read this [guideline](https://github.com/glinscott/fishtest/wiki/Creating-my-first-test) first, where the basics of Stockfish development are explained.