Re: [Bug-gnubg] Optimal settings for MacBookPro

[Philippe Michel]

On Sat, 27 Nov 2010, pierre zakia wrote:

> What are the optimal settings for gnubg installed on a MacBook Pro 15" Intel 
> Core i7 2.66 GHz (April 2010 model) ?
> The build is Version 0.9.0, running on Snow Leopard (10.6.5) without any 
> problem;
>
> I have played changing figures in Settings/options/others/Eval threads from 1 to 
> 10, guessing 4 will be optimal. 
> But strangely enough, I got the best figure in the evaluation speed for 3, 
> larger than 110 000 000  (better than with 1 or 2) and plummeting to 40 000 000 
> with 4.
> Any clue ?

I would have guessed 4 as well, and this is what I get on a similar 
configuration (dual core with hyperthreading, running linux) :
1 thread  44000000
2         87
3         96
4        121
5         95
6        106
7        109
8        115

Maybe there was something else running on your machine that was hogging 
one thread, but if this is the case your decrease for the 5th active 
thread is much more dramatic than mine.

> What is the optimal figure to put in the Cache Size box ?

The default should be fine for anything but "long" jobs like analyzing 
matches at 4ply or long rollouts. For these it is useful to increase it 
but it won't make a huge difference. On the other hand, you probably have 
plenty of memory so increasing the cache to the maximum available in the 
GUI is almost free.

> Any other default settings I should change ?

Not really a setting, but since it looks like you built it from the 
sources, I found that compiling with the -funroll-loops option helps. This 
was with gcc, though, not Apple's clang.