[vtkusers] vtkThreadedImageAlgorithm on multi-CPU system

[David Gobbi]

Hi Peter,

Edit Common/vtkSystemIncludes.h and set VTK_MAX_THREADS to 32.  If
this change causes VTK to make full use of all your CPUs, then you
should ask Kitware if they can change it before VTK 5.6 is released.

   David


On Sat, Apr 10, 2010 at 4:41 AM, Boettcher, Dr. Peter
<Boettcher at kleintierklinik.uni-leipzig.de> wrote:
> I use a vtkThreadedImageAlgorithm image flter pipleine on a 4-core single
> processor system (WinServer2008). When I execute the same program on a
> 32-core 8-processor system (WinServer2008)I do not get any significant speed
> up. Running the code on a 2-core compared to a 4-core slows done the
> prpocess by about a half - which is what I expected. Looking on the
> TaskManager it seems that not all 32 cores are used on the multi-cpu-system.
> Similar problems occur when I run my code using Windows multithreading
> capabilities using Visual C++. Obvious speed-up from 2core to 4-core.
> Slow-down when switching from 4-core to 32-core. Could it be due to the fact
> that only 4 cores have direct acces to the memory their CPU is linked to?
>
> Any suggestion would be greatly appreciated as I am totaly frustrated with
> my 32-core server being slower than my 4-core PC.
>
> Peter.
>
>
>
> ------------------------------------
> Peter Böttcher, Dr med vet, DipECVS
> European Veterinary Specialist in Surgery
> Fachtierarzt für Kleintierchirurgie
> Klinik für Kleintiere
> Universität Leipzig
> An den Tierkliniken 23
> D-04103 Leipzig (Germany)
> Tel: +49-341-9738700
> Fax: +49-341-9738799
> email: boettcher at kleintierklinik.uni-leipzig.de