[Insight-developers] how can I verify that my code runs on several processors ?

[Kent Williams]

I don't know what processors your server contains, but it's not always 
the case that multithreading increases performance.  Intel HT processors 
in particular have problems with too many shared resources between the 
computation units.  The following article indicates that SQL Server and 
Citrix Terminal Server both perform better with hyperthreading disabled.

http://news.zdnet.co.uk/0,39020330,39237341,00.htm

I don't know how you can verify that your threads are being spread 
across different processors on your server -- perhaps someone else here 
does.   ITK's threading model generally works very well, but there may 
be cases where it does not.  For some cases -- particularly short, 
simple ITK pipelines -- threading has minimal positive, and possibly 
negative impact on performance.

Gaetan Lehmann wrote:

>
> Hi,
>
> I'm trying to measure the performances of the filter I'm writing on a  
> server with 4 processors. I'm quite surprise to see that using 
> several  threads seem to decrease the performances, as it do on a host 
> with a  single processor.
> How can I verify that the different threads are running on several  
> processors ? It's not fully related to ITK, but I hope someone will 
> be  able to answer that question on this list :-)
>
> I'm running my tests on linux.
>
> Thanks,
>
> Gaetan
>
>