X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=Readme.md;h=e60ac7185d7532a278e2b7856fe6e62cf6825fe6;hp=be3247639b7e7fa404d20715b0cba3f1e808676d;hb=bf5ce1c214f8f8e3f98e5e3ac43db0dd28617e35;hpb=d39bc2efa197ba2fd55b68eced1c60bcfe2facc1 diff --git a/Readme.md b/Readme.md index be324763..e60ac718 100644 --- a/Readme.md +++ b/Readme.md @@ -42,7 +42,7 @@ Currently, Stockfish has the following UCI options: 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. @@ -55,7 +55,21 @@ 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 @@ -129,21 +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 @@ -153,12 +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. @@ -170,7 +222,7 @@ 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). +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.