topic Bug in MKL 10.2.2.025 in Intel® oneAPI Math Kernel Library

Bug in MKL 10.2.2.025

dbacchus — Mon, 16 Nov 2009 20:24:11 GMT

MKL version: 10.2.2.025
IFC version: 11.1.051
Platforms: linux x64, win7 x64

Problem: Solve large eigenproblem for the bottom few eigenstates
Matrix: real symmetric, sparse (2D finite differences of stationary state Schrodinger equation)
Method of solving: ARPACK or FEAST

ERROR: the returned eigenvectors (not eigenvalues) are wrong

1) The error is observedonly in MKL 10.2; when linked with MKL 10.1 (specifically 10.1.1.022), the code works fine.
2) The error is observed only in PARALLEL version of MKL and only when mkl_num_threads>1; when mkl_num_threads=1 or when the code is linked with the sequential MKL version,the codeworks fine.
3) The error is platform independent (observed in both linux x64 and win 7 x64)
4) The error is observedwhile using two (completely different and independent apart from their partial reliance on MKL)eigenproblem solvers: ARPACK and FEAST. In ARPACK theerror can be further pinpointed to DSEUPD (returning wrong eigenvectors).I'm not familiar with FEAST well enough to track it down to a more specific routine, but it also returns wrong eigenvectors with MKL 10.2 (works just fine with 10.1)

Note (perhaps it will help you to find the bug faster): The error has a threshold for the number of eigenvalues. For example,when the total number of states is around 17,091 and the computed number of eigenstates (N_eig) is less than 106 both ARPACK and FEAST work just fine. With N_eig>105 the returned eigenvectors are wrong. I.e. for smaller problems even parallel MKL 10.2 works fine, while for larger problems it fails.

Re: Bug in MKL 10.2.2.025

Gennady_F_Intel — Tue, 17 Nov 2009 05:26:14 GMT

Quoting - dbacchus

dbacchus,
based on the description you provided, this is a known problem and this issue has been already fixed.
The fix will available the nearest release. But, for checking the problem, can you please send us a reproducible test case?
--Gennady

Re: Bug in MKL 10.2.2.025

dbacchus — Wed, 18 Nov 2009 17:32:29 GMT

Quoting - Gennady Fedorov (Intel)

A test case would involve usage of ARPACK or FEAST library, which aren't part of MKL, plus a construction of relatively large matrices (since as I mentioned there is a threshold below which it works fine).

Can you tell us when, approximately, the new release is going to be available?

Thanks.

Re: Bug in MKL 10.2.2.025

Gennady_F_Intel — Thu, 19 Nov 2009 06:43:49 GMT

Quoting - dbacchus

the expected timeframe is during one month. i will inform you via this tread and/or announce about that on the forum.
--Gennady

Re: Bug in MKL 10.2.2.025

Gennady_F_Intel — Tue, 22 Dec 2009 15:28:17 GMT

Quoting - dbacchus

Hello dbacchus,
Intel MKL 10.2 Update 3 is now available.
The problem discussed into this tread has been fixed into this update.
Please see the Intel MKL 10.2 Update 3 is now available announce. You can find there the link to the Intel registration center to download
Could you please let us know if the problem is still exists?
--Gennady

Re: Bug in MKL 10.2.2.025

dbacchus — Fri, 25 Dec 2009 17:38:31 GMT

Quoting - Gennady Fedorov (Intel)

The problem is gonewith 10.2.3! Thanks very much!!

UPDATE: I checked both ARPACK and FEAST - and both return correct eigenvectors now.