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[Tom Casanovas]

I was surprised by the performance of Stockfish 120331 PeterPan (Izak) with 6 real cores (+ 2 HT) and I decided to repeat the test. Here you have the results:

I7 980 3.33 Ghz.
Critter, Houdini, Deep Rybka 6 real cores - NO HT
Stockfish120331 AMD 6 real cores + 2 HT
GUI: Fritz 12
Book: Perfect 2012
Time control: 2 minutes +2 sec/ game.
Ponder: Off
No tablebases

Stockfish 120331P8Amd - Critter 1.4a 64-bit SSE4(x6) 20.5 - 19.5 +9/=23/-8 51.25%
Stockfish 120331P8Amd - Deep Rybka 4.1 SSE42 x64 (x6) 23.5 - 16.5 +11/=25/-4 58.75%
Stockfish 120331P8Amd - Houdini 2.0c Pro x64(x6) 18.5 - 21.5 +7/=23/-10 46.25%

http://www.mediafire.com/?sm3m8vj19cpfnyr

Previous match under the same conditions (AMD compile):

Stockfish 120331P8Amd - Critter 1.4a 64-bit SSE4(x6) 21.0 - 19.0 +11/=20/-9 52.50%
Stockfish 120331P8Amd - Deep Rybka 4.1 SSE42 x64 (x6) 21.0 - 19.0 +11/=20/-9 52.50%
Stockfish 120331P8Amd - Houdini 2.0c Pro x64(x6) 18.0 - 22.0 +7/=22/-11 45.00%

http://www.mediafire.com/?nwfcsilebo9scbf

If we add the previous match I did under these conditions, we have that

AFTER 240 GAMES THE GLOBAL RESULT IS:

Stockfish 120331P8Amd - Critter 1.4a 64-bit SSE4(x6) 41.5 – 38.5 +20/=43/-17 51.87%
Stockfish 120331P8Amd - Deep Rybka 4.1 SSE42 x64 (x6) 44.5 – 35.5 +22/=45/-13 55.62%
Stockfish 120331P8Amd - Houdini 2.0c Pro x64(x6) 36.5 – 43.5 +14/=45/-22 45.62%

AVERAGE GLOBAL RESULT: 51.04%

I know that 240 games are not enough to prove anything, but this is the strongest version of Stockfish I have tested till now. Please note that:

- The INTEL version seems to be much weaker (although my computers are INTEL based!)
- I have added a bit of ‘doping’ with two HT cores. Although Houdini and Critter do not benefit from HT, both Stockfish and Ivanhoe play slightly better with them.
- I would appreciate if testers with very fast machines can work on this AMD version to confirm these results or not. Thanks in advance.

Regards from Barcelona.

Tom.