Response #1: 2005-08-09

General

1. Is dense linear algebra a performance bottleneck in your applications?
Yes

2. How often do your applications use the arithmetic precisions listed below:

3. What dense matrix sizes are most important or time-consuming for your application?
1,000s X 1,000s

4. Does your application come close to, or run out of memory on important problems?
Yes

5. Number of processors used for your application:

6. Which architectures do you use or intend to use in the next three years?
Sequential, Multi-core-thread, Distributed-memory, Hybrid-shared

7. Do you use any other sequential or parallel dense linear algebra packages other than LAPACK or ScaLAPACK?
fftw

8. Please rank how the following features would be useful to your current or planned applications?

9. Do your applications solve linear algebra problems of the type?
Linear positive definite systems, Banded linear systems, General linear systems, Generalized eigenvalue, Symmetric eigenvalue

LAPACK Usage

1. Do you use LAPACK (or a vendor version of LAPACK )?
Yes

4. If you use LAPACK, do you use a vendors version or one obtained directly from Netlib?
Vendor, Netlib

5. If you have used both a vendors version of LAPACK and Netlibs, how do the two versions compare?
Roughly equal, given well optimized BLAS (e.g. Atlas)

6. Do your applications make direct LAPACK calls?
Yes

7. Do your applications use libraries which depend on LAPACK?
Yes

8. Do your applications use a higher-level interface to LAPACK?
No

10. Is the LAPACK procedure interface a barrier to more extensive use?
No

11. From which languages do you call LAPACK routines?
C, C++, Fortran 77, Fortran 90/95, Python

12. Please describe any tools or helper functions that you frequently implement to assist your applications in using LAPACK?
Numeric Python

13. How could the LAPACK interface be improved to feel more natural to your application and implementation language?
Better integration with Python

14. If you have installed LAPACK yourself, how could the installation process be improved?
It could not be improved

15. How frequently do you refer to the LAPACK Users Guide?
Sometimes

16. What information in the LAPACK guide is hard to find or is missing, if any?
N/A

ScaLAPACK Usage

1. Do you use ScaLAPACK (or a vendor version of ScaLAPACK )?
Yes

4. If you use ScaLAPACK, do you use a vendors version or one obtained directly from Netlib?
Netlib

6. Do your applications make direct ScaLAPACK calls?
Yes

7. Do your applications use libraries which depend on ScaLAPACK?
No

8. Do your applications use a higher-level interface to ScaLAPACK?
No

10. Is the ScaLAPACK procedure interface a barrier to more extensive use?
Yes

11. From which languages do you call ScaLAPACK routines?
Fortran 77

12. Please describe any tools or helper functions that you frequently implement to assist your applications in using ScaLAPACK?
None, although I'd like some

13. How could the ScaLAPACK interface be improved to feel more natural to your application and implementation language?
Better interface to Blacs. The redist utils are a great start, but they're poorly documented, and frequently when the system administrators install scalapack they don't even know that they should also build redist.

14. If you have installed ScaLAPACK yourself, how could the installation process be improved?
It's pretty good, although I recall having to go through a lot of configuration tweaking to make it work. Autoconf might help here.

15. How frequently do you refer to the ScaLAPACK Users Guide?
Very Frequently

16. What information in the ScaLAPACK guide is hard to find or is missing, if any?
redist!! Plus, information *about* redistributing matrices with/without the redist utilities. Scalapack is of no use to anyone if people can't get their matrices distributed on the computers.

Targeted Environment Specifics

1. Under which operating system environments do your applications run?
Linux, Mac OS X

3. If your applications run in a distributed-memory environment, which styles of parallelism do they employ?
Message passing

Additional Information