This is taken from Mr. Houdart's website. http://www.cruxis.com/chess/houdini.htm

Tuning the Split_Depth parameter on 4-core and 8-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 ...

Googled: rybka hyperthreading

Most recent thread. http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=17836

Googled: houdini hyperthreading

http://www.open-chess.org/viewtopic.php?f=7&t=461&start=10#p3992

http://www.open-chess.org/viewtopic.php?f=7&t=461&start=10#p3994

I'm not saying ...

I wish that people who know about this stuff would give us definite answer.
In the future when engines are able to use MT than 8 cores will be helpful .
I'm sure I've read both Houdard and Vas writing it was better to use 4 cores. I'l try to find the links. Also, how does Houdini 4-core compile ...

kingliveson wrote: Actually, I no longer have IvanHoe 9.53b w32 source code. I was careless, but am definitely keeping the source for the next build though. Inside joke.

Can't you decompile it and make it even stronger?

Works fine. Thanks.

Ivanhoe 9.53b x32 default doesn't run on older pcs because popcnt is turned on---when I run the exe in a dos window, it reports popcnt enable.

here's the download link for the 8_CPU version compiled with lockless hash table access ("Hyatt hashing"): http://www.cruxis.com/chess/download/Houdini_103a_x64_LOCKLESS_8CPU.zip

It may or may not solve the performance problem on the x5355 hardware, please keep me updated about success or failure ...

If this processor is a double quad core with shared memory, the memory contention of the spin locks could absolutely kill the performance.
For this kind of architecture the "lockless hashing" promoted by Bob Hyatt should be used. I have since long coded the hashless locking in Houdini, but haven't ...

I found some games here. http://www.open-chess.org/viewtopic.php?f=4&t=36&start=10#p1484

[White "Houdini 1.01 x64 8_CPU"]
[Black "IvanHoe-B 63Mod12c"]
[Result "1/2-1/2"]
[TimeControl "600"]

{AMD Phenom(tm) II X6 1090T Processor 3895 MHz
W=21.8 plies; 9,350kN/s; Perfect 2009.ctg
B=21.6 plies; 10 ...

sirabc wrote:1.03 with a Intel Xeon X5355 Octa (8x2660 MHz)

Update: Task manager reported 8 cores at 100%. Something maybe wrong with the 8 core version.

On another board, someone tested 1.03 with a Intel Xeon X5355 Octa (8x2660 MHz). The node count was around 3.3 mn/s. Ivanhoe is around 7 mn/s. I've asked the tester whether Houdini was playing with only 4 cores, will post an update.