Computing

Our interest in parallel computing is motivated by our investigations of QCD using the transverse lattice method. It is also used in the Parallel Computing (CSC491) class.

Parallel lanczos

Development of parallel lanczos methods for finding the lowest eigenvalues of sparse matrices. This research was conducted by Geneva undergraduate students George McDaniel and Loren Silbaugh during the summer of 2000.

plan3.tgz is the resulting package of Lanczos routines for finding eigenvalues (and eigenvectors) of symmetric-real and complex-hermitian sparse matrices. It has both a single-processor and a parallel version. It is based on the PLANSO package by Wu and Simon.

Semi-definite eigenvalue problem

In light-front quantization, one often has fields that are constrained, not true dynamical degrees of freedom. If one keeps constrained states in the system, the resulting eigenvalue problem has the form

A x = lambda E x

where A and E are Hermitian and E is positive semi-definite. Currently, we assume E is also diagonal.

During the summer of 2004, Geneva student Justin Lambright developed numerical methods for solving these problems. See Justin Lambright's project summary (PDF) (LaTeX).

As detailed in the project summary, we developed a dense version semidefinite.f, and a sparse version sparsesd.tgz which uses SPOOLES and plan3.tgz. A second sparse version blocksparse.tgz assumes the constrained part of the matrix is block-diagonal; it does not use SPOOLES. We have not yet parallelized this code.

See libaries by Yousaf Saad in Duluth

Beowulf Cluster

During June 2003, we set up an 8-node beowulf cluster using 16 AMD Opteron processors and 32 GBytes of memory. As of August 2004, the operating system is a modification of Fedora 2 for x86-64. It is configured so that one node acts as file server for the other seven nodes, which are diskless.

The computers are connected via two parallel Gigabit Ethernet networks. During the summer of 2004, extensive benchmarking of the system was performed by Geneva student Jeremy Pace. Here is his summary of activities (PDF) (LaTeX).

Other Linux Stuff

Setting up proxy ARP for just some interfaces is slightly tricky. Including echo 1 > /proc/sys/net/ipv4/conf/eth?/proxy_arp in rc.local won't work for network restarts. Instead, here is a script that will be run automatically on startup: /sbin/ifup-local.
Set the region on your DVD drive dvd_set.c.
disk_backup is a shell script for performing incremental backups. Normally it is run daily as a cron job.

Brett van de Sande,
Homepage: http://www.geneva.edu/~bvds and
E-mail: bvds@pitt.edu