Re: [Boost-users] number cores / cpu

Subject: Re: [Boost-users] number cores / cpu
From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2010-08-23 10:00:29

Kraus Philipp wrote:
> 
> Am 23.08.2010 um 15:02 schrieb Lars Viklund:
> 
>> On Mon, Aug 23, 2010 at 02:57:49PM +0200, Kraus Philipp wrote:
>>> can I determine how many physical cpu and cores are installed in a
>>> system with the boost lib?
>>
>> There's thread::hardware_concurrency() which will give you a count of
>> hardware threads.
>>
>> Personally, if I wanted more specific knowledge, I'd use /proc on Linux,
>> WMI on Windows, etc., conditionally compiled.
>>
>> [1] 
>> http://www.boost.org/doc/libs/1_44_0/doc/html/thread/thread_management.html#thread.thread_management.thread.hardware_concurrency 
>>
> 
> Thank. I need exactlly this number

Just beware, IIUC, that the returned count includes hyperthreads(intel). 
Which if used to set up a thread pool may lead to surprisingly poor 
performance. Getting the true core count is more involved.

Jeff