X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=Readme.md;h=35ff095d6792857cc8db58ba84c734aaeba52644;hp=a759eff665bc9e65e64b578b77c6dcf6532bf07a;hb=d4763424d2728fe2dfd0a6fe747666feb6a2fdbb;hpb=86ee4eb84d54dac3f9de5b455ba41909c7722173;ds=sidebyside diff --git a/Readme.md b/Readme.md index a759eff6..35ff095d 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. @@ -138,6 +138,30 @@ 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