Setting threads for Stockfish 6 in Arena

[Modern Times]

Really strange design, that UCI engines obey a different Threads setting than WinBoard engines...

Has nothing to do with UCI. UCI-wise it's just

Code: Select all

setoption name Threads value X

If Arena doesn't allow to set UCI options normally, then Arena is at fault, not SF nor UCI.

Yes, this is all about the GUI.

Some GUIs have a common threads setting, others don't. Shredder GUI doesn't for example.

If the GUI has it, then it is essential that it can be deactivated, in case you want to say run a 1CPU engine against a 4CPU engine.

[Wolfgang]

....then it is essential that it can be deactivated, in case you want to say run a 1CPU engine against a 4CPU engine.

Yes, it can!

After that you can change the value for number of CPUs via engine options as described by Sedat for Arana 3.0.

It's exactly the same handling as with hash size. If you deactivate the "hash for all" menue point you can change hash size via engine options and play e.g. Engine A with 128 MB vs. Engine B with 256 MB (for which reason ever you want to do that...)

[Sedat Canbaz]

How do I set the number of threads for Stockfish in Arena?
Under the engine configuration there is no thread switch.

Here is the configuration:
1) Open Arena GUI
2) Click from the menu tab 'Engines'
3) Manage
4) Select Stockfish
5) Start this engine right now
6) Right-Click over Stockfish

And then you can increase the cores (the default is 1)

Note also you need to restart the engine to take effects




Hopes helps,
Sedat

I think you're describing how it works in Arena 3.0.

In version 3.5, you have a common setting for the number of threads. The thread setting doesn't appear in the configurable UCI options, as shown in your graphic.

Yes...I use Arena 3 GUI (instead of Arena 3.5)
According to my experience, I found Arena 3 to be more stable...

Be aware in that too,
Arena's common settings in both GUIS (v3 and v3.5) does not work properly
I mean sometimes the common setting does not work...
Especially the MP engines (which use Auto cores) use maximum cores, even if the common setting is set to 1 core
Even sometimes the common setting for hashtable size does not work too

But there is a solution (as always)
I use separately setting for each engine (shown in the picture)
For more details please see the useful recommendation by Anteras:
http://rybkaforum.net/cgi-bin/rybkaforu ... ?tid=28946

In this way,
All is ok...engines play without any problems...

Best,
Sedat

[Modern Times]

....then it is essential that it can be deactivated, in case you want to say run a 1CPU engine against a 4CPU engine.

Yes, it can!

After that you can change the value for number of CPUs via engine options as described by Sedat for Arana 3.0.

Yes agreed. I don't use Arena, but I've had a look through the screens.

[Sedat Canbaz]

Note also you need to restart the engine to take effects

Is this a Stockfish bug or an Arena bug?

I think this is not a bug...
But otherwise each time the engine will use the default setting

But with restarting...you don't need to run each time manually...

Best,
Sedat

[Sedat Canbaz]

Here is my setting for engines, which use 1 core (by default):






.
Another setting for MP engines, which use auto cores (by default):

[hgm]

And if it is confirmed it can only be an Arena bug, because once you send:

Code: Select all

setoption name Threads value X

SF immediately resizes the thread pool.

OK, thanks, that was my question. So if it indeed needs a restart in Arena then apparently Arena des not immediately send the option setting to the engine, when the user changes the option value.

I think that should qualify as a bug. Users won't change the Threads setting just for fun, but because they want the engine to use a different number of threads, They have the right to expect that this command is oeyed without being forced to do any other kind of trickery.

Of course when an engine is restarted for another reason (e.g. in a tourney) it should automatically receive the threads and hash settings configured by the user too, and not left to use its own default. If you run in a mode where a centralized GUI setting is supposed to work for all.

[Joerg Oster]

And if it is confirmed it can only be an Arena bug, because once you send:

Code: Select all

setoption name Threads value X

SF immediately resizes the thread pool.

OK, thanks, that was my question. So if it indeed needs a restart in Arena then apparently Arena des not immediately send the option setting to the engine, when the user changes the option value.

This is of course not true. Just like it should be, Arena immediately sends the setoption command to the engine. No need at all to restart an engine!

[snino64]

I use Arena 3.5 from linux with wine and this is the problem: I have not the threads option (Arena 3.5)

www.labagacera.es/Imagen_chess/Arena-Stockfish.jpg

[royb]

I use Arena 3.5 from linux with wine and this is the problem: I have not the threads option (Arena 3.5)

www.labagacera.es/Imagen_chess/Arena-Stockfish.jpg

If you go to Engines -> Manage and click on the UCI tab, at the bottom of that window is a checkbox with the label "Common max CPU cores setting". Uncheck that box and then bring up the engine configuration for (in this case) Stockfish. The "threads" option now appears.

And I am also running Linux with Wine and Arena 3.5.