Hardware: Dual AMD Opteron 6376, 32 x 2.3 GHz (Turbo Core off)
OS: Windows 7 Pro 64-Bit
GUI: no
Settings: all engines default settings
Large Tables: no
Position: starting position
Time: 20 seconds
UCI commands:
setoption name threads value 1 (to 32)
go movetime 20000
The tests were run in console mode.
Here the values from 1 to 32 threads, starting position, with 20 seconds of computing time.
nps = nodes per second

Komodo, Houdini and Zappa are almost equal up to 16 threads (factor 11.94 - 11.37 - 11.34).
Stockfish DD and also the latest Stockfish version lies somewhat behind (factor 8.01 - 9.79).
Komodo scales still excellent beyond 16 threads. Also Zappa shows a very good SMP implementation.
Beyond 16 threads Houdini and Stockfish DD benefit much less than the other tested engines.
Increase from 16 to 32 threads:
Komodo TCECr (11,94 - 20,60 = 73%)
Zappa Mexico II (11,37 - 16,46 = 45%)
Stockfish 140513 ( 9,79 - 14,21 = 45%)
Stockfish DD ( 8,01 - 10,18 = 27%)
Houdini 4 Pro (11,34 - 13,48 = 19%)
