topic IPP uses only a single thread in Intel® Integrated Performance Primitives

IPP uses only a single thread

snirgaz — Tue, 15 Feb 2011 07:30:14 GMT

Hi all,

I am using a few IPP function in my c++ code (cos. log, exp add mul etc.) on an 8 core machine.

I am linkind with the ipp=common option.

For some reason the calculation is done using only a single thread.

I tried using:

ippSetNumThreads(8);

But I only get a single core usage with:

ippGetNumThreads(&t);

Any idea want I am missing?

Thanks !

Snir

IPP uses only a single thread

Ying_H_Intel — Wed, 16 Feb 2011 02:07:11 GMT

Hi Snir

You may run same problem asjaylord in http://software.intel.com/en-us/forums/showthread.php?t=77146.

The key problem should make sure if the linked ipp libraries arethreaded libraries
for example,
ipp*.a are static serial library
ipp*_l.a are static threaded library
(make sure callippStaticInit() before any other Intel IPP function when linking static library ) ;

ipp*.so are threaded dynamic library.

Hope it helps,
Ying H.

IPP uses only a single thread

snirgaz — Wed, 16 Feb 2011 05:51:18 GMT

Hi,

Thanks a lot for the quick reply!

I am using IPP 7.0 and linking dynamically, according to the Documentation (and your reply) they should be automaticly threaded.

any clue?

Snir

IPP uses only a single thread

Vladimir_Dudnik — Wed, 16 Feb 2011 10:40:01 GMT

Hu Snir,

not every function in IPP will use threading internally, please check with ThreadedFunctionsList.txt file to see if you can expect using threading in functions of your interest (the file is located in IPP documentation folder of your installation)

Regards,
Vladimir

IPP uses only a single thread

fishbupt — Thu, 05 Jan 2012 06:40:33 GMT

Hi,

I have some problem when using IPP running on my new i7-2720QM processors.

I used ippSetNumThreads(&numThreads), which got 8. But ipp function always use single threads on my

laptop with i7-2720QM.

The same executable binary run well on my desktop with i7-920 using 8 threads.

Any suggestion?

IPP uses only a single thread

SergeyKostrov — Fri, 06 Jan 2012 13:55:28 GMT

Did you checkin the WindowsTaskManager how many threads were actually created for your application?

Best regards,
Sergey

IPP uses only a single thread

igorastakhov — Sun, 08 Jan 2012 09:51:03 GMT

please provide additional info: IPP library version:

static void libInfo( void ){

const IppLibraryVersion *lib;

lib = ippiGetLibVersion();

printf( "CPU : %s\n", lib->targetCpu );

printf( "Name : %s\n", lib->Name );

printf( "Version : %s\n", lib->Version );

printf( "Build date: %s\n", lib->BuildDate );

}

and function(s) you are using.

Regards,
Igor

IPP uses only a single thread

igorastakhov — Sun, 08 Jan 2012 09:52:40 GMT

sorry, one addition: - of course for both CPUs - in order to be sure the same code is working on both.

Regards,
Igor