Gull 3.0.1 available, takes advantage of hyperthreading

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Gusev
Posts: 1475
Joined: Mon Jan 28, 2013 1:51 pm

Gull 3.0.1 available, takes advantage of hyperthreading

Post by Gusev » Thu Jan 21, 2016 8:37 pm

I made Gull 3.0.1 available for download at http://www.firenzina.org/Gull_3-0-1.zip. Gull 3.0.1 is a very minor modification of Gull 3 that has two extra features:
1. Gull 3.0.1 is compatible with MinGW and Dev-C++ (with TDM). It would be great if some kind soul decided to set up a website for Gull MinGW auto-compiles like the one that Stockfish has at http://abrok.eu/stockfish/. The scripts currently included need to be modified in order to support auto-compilation with PGO.
2. Gull 3.0.1 no longer prevents the number of threads (processes, actually) from being 2 times the number of cores on Intel computers that support hyperthreading (HT). This is done for FOSCEC Season 3, where I intend to keep HT on. Coincidentally, Vadim's code that used to check for hyperthreading was incompatible with the compilers used by MinGW and Dev-C++.
I verified that the strength of the MSVC compiles is the same as Gull 3 when the number of threads is the same. A 16-thread Gull 3.0.1 AVX2 beats an 8-thread Gull 3 BMI2 on an 8-core i7-5960X narrowly, 1011.5/2000 360-337-1303 (+4 Elo). TC 20"+0.3", Hash 256MB, HT on. An 8-thread Gull 3.0.1 SSE2 did even better (~+14 Elo) against a 4-thread Gull 3 on a quad, I will post the details later.

crossroads
Posts: 11
Joined: Wed Apr 23, 2014 1:25 am

Re: Gull 3.0.1 available, takes advantage of hyperthreading

Post by crossroads » Thu Jan 21, 2016 10:30 pm

Do you have plans to add Syzygy in the near future?

Gusev
Posts: 1475
Joined: Mon Jan 28, 2013 1:51 pm

Re: Gull 3.0.1 available, takes advantage of hyperthreading

Post by Gusev » Fri Jan 22, 2016 12:04 am

Gull_3-0-1_YC_x64_SSE2_MSVC (8 threads) - Gull 3 x64 (4 threads): 1045.5/2000 409-318-1273 (+16 Elo), i7-930 quad, TC 20"+0.3", Hash 256MB, HT on.
Gull_3-0-1_YC_x64_SSE2_MSVC (4 threads) - Gull 3 x64 (4 threads): 500.5/1000 151-150-699 (0 Elo), same conditions. The result on i7-5960X, AVX2 vs BMI2, 8 threads each, was very close to this one, also 0 Elo difference.
The bottom line is, you want Gull 3.0.1 instead of Gull 3 if you don't want to turn off hyperthreading (HT) on your Intel processor. Then you can gain several Elo points by running more processes. Other than that, no difference in strength achieved.

Gusev
Posts: 1475
Joined: Mon Jan 28, 2013 1:51 pm

Re: Gull 3.0.1 available, takes advantage of hyperthreading

Post by Gusev » Fri Jan 22, 2016 12:08 am

The problem is, someone tried, unsuccessfully so far, it seems. I have no plans to take over Gull as a project. Gull 3.0.1 is developed for FOSCEC Season 3 coming soon, where I anticipate running 16 threads on an 8-core machine with hyperthreading on. Gull 3 wouldn't do that.

overlord
Posts: 198
Joined: Sun Jun 03, 2012 4:46 pm
Location: Trinec, Czech Republic

Re: Gull 3.0.1 available, takes advantage of hyperthreading

Post by overlord » Sat Jan 23, 2016 9:33 am

It would be really nice if somebody could continue Gull project.

Dan Cooper
Posts: 184
Joined: Sun Nov 01, 2015 2:15 am

Re: Gull 3.0.1 available, takes advantage of hyperthreading

Post by Dan Cooper » Sun Jan 24, 2016 1:37 am

overlord wrote:It would be really nice if somebody could continue Gull project.
http://talkchess.com/forum/viewtopic.php?t=58299

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