My quad core MacPro was at the top until an hour ago

[sje]

My quad core MacPro was at the top of Apple's profesional model line until an hour ago. The octo core Cloverleaf Xeon model has been announced. See:

http://www.apple.com/macpro/

The base 3 GHz octo core starts at US$3,997, rather more than I paid for my 2.66 GHz quad core. My model is still available at the same price (US$2,499).

[rafowell]

My quad core MacPro was at the top of Apple's profesional model line until an hour ago.
The octo core Cloverleaf Xeon model has been announced. <snip>

Between this April 4 Mac hardware upgrade, and the April 2 Mac chess software upgrade
(introduction of HIARCS 11.1 MP for Mac),
http://216.25.93.108/forum/viewtopic.ph ... 94&t=12843

the horsepower limit on Macintosh chess has gone up quite a bit!

What Mac Chess software takes advantage of multiple CPUs?

I'm aware of:
HIARCS 11.1 MP
http://www.hiarcs.com/mac_chess_hiarcs.htm

Deep Shredder 9 Mac
http://www.shredderchess.com/chess-prog ... 9-mac.html

I know that Glaurung 1.2.1 runs multiprocessor on PCs, but
I don't know that the Mac version does:
http://www.glaurungchess.com/

[krazyken]

Glaurung does indeed support MP. Also available are Crafty, and Scorpio, although I haven't tried the most recent versions.

[Tord Romstad]

I know that Glaurung 1.2.1 runs multiprocessor on PCs, but I don't know that the Mac version does:

Of course it does: Mac OS X is Glaurung's native platform. I do all the development on my Macs (an iMac and a MacBook, both 2 GHz Core Duos).

Glaurung won't be able to utilize the new eight-core MacPro, though: The maximum number of threads in Glaurung is currently 4. It is possible to compile a Glaurung binary with 8 threads simply by changing the constant MaxNumOfThreads (defined near the top of glaurung.h) from 4 to 8, but I'm afraid the performance will be disappointing. Bob ran some benchmarks with Glaurung on the 8-core Opteron he used for Crafty in the WCCC last year, and it turned out that Glaurung was only a tiny bit faster with 6 threads than with 4, and actually slightly slower with 8 threads than with 6.

I have later fixed an SMP bug which hurts Glaurung's performance with 3 or more threads (this bug fix is not included in the public 1.2.1 version), but even with this bug fix, I doubt that Glaurung will be much faster with 8 threads than with 4.

Utilizing 8 CPUs well takes a lot of careful tuning , which is difficult to do without having a 8 CPU computer to play with. There will probably be an optimized Glaurung for 8 CPUs shortly after Apple releases an 8-core iMac (I can afford a Mac Pro, but not a house big enough to contain one. These things are huge!).

Nevertheless, if someone buys one of the 8-core Mac Pros, it would be nice to see some benchmarks. Please let me know, and I'll send a binary (or the source code, if you prefer) with support for 8 threads and the previously mentioned bug fix.

Tord

[sje]

A correction: it's Clovertown, not Cloverleaf. Intel takes it's chip names from the names of rivers in the US Northwest.