Default value for numCapabilities?

[Bulat Ziganshin]

Hello Dimitry,

Tuesday, April 27, 2010, 8:09:49 PM, you wrote:

a few months ago i asked SimonM about using all cores by default, but
he said that it dramatically reduces performance in some cases

> Hi,

> As a followup to the discussion [1] about the portable way to find the
> number of CPUs/cores: how is the default value of numCapabilities [2]
> set when +RTS -N is not on the command line?

> Does GHC runtime figure out the number of cores itself, or it is by
> default 1 unless specified on the command line?

> Thanks.

> ---------------------------
> [1] http://haskell.org/pipermail/haskell-cafe/2010-April/076911.html
> [2]
> http://hackage.haskell.org/packages/archive/base/latest/doc/html/GHC-Conc.html#v:numCapabilities




-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com