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The package contains Houdini_15_w32.exe for 32-bit Windows (up to 4 cores) and Houdini_15_x64.exe for 64-bit Windows (up to 8 cores).
Each executable contains code for optimal execution from single-core up to the maximum number of cores. On a 64-bit platform the 64-bit version is about 30% faster than the 32-bit version. If your hardware supports SSE4.2 the program will use the POPCNT instruction for another slight performance gain.
mirror link
http://hotfile.com/dl/89682474/092b340/Houdini_15.zip.htmlWhat's new in Houdini 1.5
Improved Evaluation and Search
Positional evaluation and search algorithm have been improved to make this by far the strongest Houdini ever.
Single executable
Previous releases had different executables depending on the number of cores or the availability of SSE4.2 extensions. In Houdini 1.5 all the code has been integrated into a single executable for each platform (32/64-bit).
Gaviota End Game Table Base support
Houdini 1.5 integrates Gaviota end game table base support, see below for more details.
Configurable Contempt
The notion of "contempt" implies that Houdini will try to avoid draws during game play. The Contempt level can be chosen between 0 (none) and 2 (aggressive), the default value of 1 should be a good compromise in most situations.
The Analysis_Contempt option will activate the Contempt for position analysis, this is usually not recommended.
Large Page Support
There is no longer a separate UCI option for large memory pages. If large memory pages are available they will be used, see below for how to configure Windows to enable this feature.
Clear Hash button
A new Clear Hash button is available in the UCI interface.
Gaviota End Game Table Base (EGTB) support
Houdini integrates the Gaviota EGTB probing code
Miguel A. Ballicora. All information about Gaviota EGTB files can be found at the Gaviota web site.
Even without EGTB Houdini is a great performer in the end game because of its extensive built-in knowledge of basic endings (e.g. KQ v KP and KB v KBP). Knowing that the EGTB access is very slow compared to a native evaluation of the position, a generic use of EGTB might actually decrease the playing strength. To cope with this situation Houdini will vary the frequency at which the EGTB are probed depending on the end game that is occurring. In difficult endings in which the table bases are very useful (e.g. KQP v KQ or KRP v KR) Houdini will probe the EGTB files much earlier than in endings that are easy to evaluate.
The location of the Gaviota EGTB files is specified in the GaviotaTbPath option. Houdini will scan the folder for "kqkr.gtb.cpX" files and accordingly decide which compression level to use.
The depth of the earliest probe of an EGTB can be configured with the Hard_Probe_Depth and Soft_Probe_Depth options. In a multi-core environment you may want to increase these values to reduce the likelihood of several cores probing the EGTB simultaneously.
Houdini will always probe the EGTB for the initial position of the search. If an EGTB mate position is identified, the full main line will be shown immediately. If the initial position is an EGTB draw but Houdini has a material advantage, Houdini will still play for a win - the opponent might be human or an engine without end game table bases.
UCI Options
The following UCI options are available:
* Hash: Amount of hash table memory used by the program in MB. Default 128, min 4, max 1024/16384 (32/64-bit).
* Threads: Maximum number of cores used by the analysis. Default is hardware-dependent, min 1, max 4/8 (32/64 bit).
* Split_Depth: Minimum depth at which work will be split between cores, see below. Default 10, min 8, max 99.
* Ponder: [game play only] Have the engine think during its opponent's time. True (1) or false (0).
* Contempt: Level of contempt to avoid draws in game play. Default 1, min 0 (none), max 2 (aggressive).
* Analysis_Contempt: [position analysis only] Activate Contempt in position analysis. True (1) or false (0).
* MultiPV: [position analysis only] Number of principal variations shown. Default 1, min 1, max 16.
* GaviotaTbPath: Folder containing Gaviota EGTB files
* GaviotaTbCache: Amount of Gaviota EGTB cache memory in MB. Default 64, min 4, max 1024.
* Hard_Probe_Depth: Minimum depth at which a hard EGTB probe is performed. Default 24, min 2, max 99.
* Soft_Probe_Depth: Minimum depth at which a soft EGTB probe is performed. Default 16, min 2, max 99.
Tuning the Split_Depth parameter on multi-core hardware
The Split_Depth parameter defines the minimum depth at which work will be split between cores. This parameter can impact the speed of the engine (nodes per second) and should be fine-tuned to get the best performance out of your hardware.
The default value 10 is tuned for quad Core i5/i7 systems, but on other systems it may be advantageous to increase this to 12 or 13. To select the best Split_Depth for your system you should analyze some positions for a fixed duration (e.g. 30 seconds) and measure the average nodes/second. Do this for all values of Split_Depth between 10 and 14, and keep the value that produces the highest average node speed.
Large Memory Pages
Houdini will use so-called large memory pages if they are provided by the operating system. Depending on the hash table size the speed improvement may be between 5% and 20%.
To enable this feature in Windows, you need to modify the Group Policy for your account:
1. Run: gpedit.msc (or search for "Group Policy")
2. Under "Computer Configuration", "Windows Settings", "Security Settings", "Local Policies" click on "User Rights Assignment"
3. In the right pane double-click the option "Lock Pages in Memory"
4. Click on "Add User or Group" and add your account or "Everyone"
5. You may have to logoff or reboot for the change to take effect
You'll also need to run your chess GUI with administrative rights ("Run as Administrator") or disable UAC in Windows.
Very often large pages will only be available shortly after booting Windows. After a while the Windows memory becomes too fragmented for large page allocation, and Houdini will fall back to standard memory page usage