Re: [Bug-gnubg] GnuBg only uses one Core (linux)

[Philippe Michel]

On Fri, Apr 05, 2019 at 03:44:23AM +0200, Philippe wrote:
> Hello,
> 
> I have installed GnuBG 1.06.001 Feb 28 2018 from the Ubuntu software center.
> 
> The problem is that it uses only one thread despite the "about" menu
> states that multi threading and SSE/SSE2 are enabled.
> 
> Compiling with Xubuntu 18.04 the latest 1.06.002 version gives the same
> result. I read here http://boray.se/gammon/linux.html that the Windows
> version has not this problem. This is true because I tested it in Windows.
> 
> So can you explain how to get multi threads ?

Using only one thread is the default (but it should be the case on 
Windows as well).

Check the "Eval threads" field in the Settings/Options/Other menu and 
see if the value there is indeed at 1 on your Linux system but may have 
been set to something else in your Windows account at some point.

The tooltip for this field ("this should be set to the number of logical 
processing units available") is a bit misleading on two accounts :

- it is not set to this number automatically

- since multithreading applies only for match analyses or rollouts, both 
potentially long tasks, you may use your computer for something else at 
the same time and prefer setting eval threads to a value lower than that 
to give priority to the latter tasks' responsiveness.