Winboard Forum

After a long time I analysed some positions from the last team match of my club and used for the first time all of the cpus
of my quad. I analysed the positions with latest GradualTest by Odd Gunnar Malin which understands UCI and all went well
with Rybka 4 and Stockfish 1.91JA, but I was a bit surprised by the depth difference between both, even when knowing that
Rybka neglects 3-5 ply in counting for one cpu.(Task manager check showed that all was ok though, because Stockfish used
99% in one process and Rybka 4*25% in 4 processes...)
I did some experiments launching Rybka in PSWBTM and watching the Taskmanager and to my astonishment it used only one core
in this configuration using WB 4.42 and an older Polyglot (1.39). The log showed that WB resetted the cores to 1 despite a different entry
in my Polyglot ini file 'Max CPUs = 4').
Was this a known bug for that version or do I need a newer Polyglot or what went wrong here?
(I could provide a log of course if needed)

Guenther

You probably had "Max Nr of CPUs" set to 1 in the WinBoard Options->Common Engine Settings dialog. WinBoard gives you the number of CPUs that you ask for there, when you use a Polyglot that supports the "cores" command. In general, settings specified in the GUI will overrule anything that is specified in the polyglot.ini file (so that you can alter the engine settings interactively). The latter just defines the default settings (of the simulated WinBoard engine), which will remain if force if the GUI will not alter them. But cores and memory size are standard options, which will always be set by the GUI, and never left at their default values (on GUIs that support this).

Thanks, you are right, cores was set to 1 in global settings. I did not notice this, because I use Polyglot the old fashioned way
and just once in the beginning set some values here, but actually never used them via GUI before.

Guenther

OK, beware that with these new versions of WinBoard + Polyglot in particlar the hash size, nr of CPUs and Nalimov path can no longer be set through the polyglot.ini file. Other parameters can still be set there, as they would only be overruled on command of the user using the Engine Settings dialogs, and you can simply refrain from using those. Although these dialogs can be used to edit the polyglot.ini file.