Intel® Math Kernel Library

dggev deterministic behaviour


I am using dggev (mkl versions 11.2.1 & 11.2.2) and i notice some non deterministic behaviour concerning eigenvalues near zero and infinite eigenvalues and eigenvectors. I use the parallel mkl version with gomp (not intel omp). I compile my code using gcc 4.4.7. It seems that there are (at least) 2 sets of output that differ in the regions mentioned. I also use mkl allocators to ensure my memory is aligned. It is a rare phainomenon, but still, could you have a look? 


Back-substitution of Pardiso not executing in parallel


In an iterative algorithm I'm reusing the factorization of a symmetric indefinite matrix to solve for different right-hand sides. The back-substitution is performed in a loop with a single right-hand side being sent to pardiso at each time.

I'm using paridiso_64 and mkl 11.1u2.

Inplace permutation


I need to permute a vector according to an index array jpvt returned by ?geqp3.  In the example lapack/source/dgeqpfx.f it is done using an auxiliary array. I would like to do the transformation inplace (or at least with O(1) extra memory), but as you can see from the attached source code, I don’t seem to be able to use ?laswp correctly. Can this be used for this kind of transformation ? If yes, how ? If no, is there another way to do this ?

Thank you in advance.


Do I need Pardiso_64? iparm(18) reports negative value

I am attempting to solve a large complex, symmetric matrix using PARDISO.  The matrix has approximately 1,000,000 equations, and 91,000,000 non-zeros.  I suspect that during Pardiso's factorization stage, the number of non-zeroes in the factors exceed the 32-bit integer size limit (i.e. 2^31).  I suspect this because pardiso returns a very large negative number for iparm(18), after the factorization stage.

So ... here's the questions.

Application Shutdown on call to DftiCreateDescriptor for Intel MKL c++

Hello all, 

I have built a C++plugin to that employs MKL's fft libraries for filtering purposes. This plugin is used by a C++ compute system that generates data on demand by any other application. This compute system is used by a C# application. When I request data of my plugin, I can debug up to my DftiCreateDescriptor call only for my application to shut down on execution of said call.

The following is the output generated:

A bug in zgelsd in MKL 15.0

Hi there, 

Thank you for reading this post. 

I got these error messages when calling zgelsd  in MKL 15.0 to solve  a fairly large matrix,

Intel MKL INTERNAL ERROR: Condition 1 detected in function DLASD4.

Intel MKL INTERNAL ERROR: Condition 1 detected in function DLASD8.

I googled online and found the exact issue here, where it said the bug had been fixed in MKL 11 update 5.

multi-threaded matrix multiplication

Dear Intel MKL developers,

I am integrating the MKL subroutine mkl_zcsrmultcsr in my MPI code. I tested a case with 16 processors, and mkl_zcrsmultcsr is called in every processor in parallel. Once it is called, multi-threaded computing is automatically activated.

The problem I encountered is that 12 processors among all processors work fine while the other 4 processors give memory corruption errors, moreover, these 4 processors can vary during each test. I am not sure what the problem would be. Your advise is well appreciated.





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