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\title{Puma Task 5.1.1: Quantum Chromodynamics\\
First Annual Technical Report}
\author{D.B. Carpenter}
\address{University of Southampton}

\begin{document}

\maketitle{}

\section{Aims}
In the immediate term the aims of this task are to implement
and run Quantum Chromo\-dyn\-am\-ics (QCD) application code on existing
transputer hardware --- both as demon\-strat\-ors for the technology
and with the intention of generating publishable scien\-ti\-fic
data.  The latter goal involves collaboration with Prof.\ C.J.
Sachrajda and his group, in the University of Southampton
Department of Physics.

Of course, in line with the aims of the PUMA project, we also
intend to provide application code which will exploit the features of
H1/C104 architectures.  In the short term this will involve porting
the now-existing software to run under the virtual channel router
produced by Workpackage 3.

Also we intend to abstract from these codes the communication
routines, which will be provided as libraries for use in
related grid-oriented applications.

\section{Progress}
In the first six months of the project QCD code developed during
the Esprit P1085 (Supernode) project was adapted to handle the
size of system needed for competitive research in this area.
The software was targetted at a Telmat Meganode system available
in Southampton.

The main problems encountered were related to the small amount of
memory available on that system (256kbytes external SRAM per
processor).  These difficulties were ex\-acer\-bated by the poor
data bandwidth between the transputer array and the mass storage
systems (disk and {\em exabyte} tape) resident on the host computer.

Nevertheless this code has now been adapted to the Meganode
system, and over the past few months we have run the code
successfully for many hundred hours.  The most computationally
intensive part of the code has been benchmarked at speeds in
excess of 110 MFLOPS on the 128 T800 array, making it competitive
with ``conventional'' supercomputer codes.

A preliminary calculation of the properties of the B-Meson is
approaching completion, and we hope the results will be
presented at a forthcoming high-energy physics conference.

Several of the problems with the existing machine will be
alleviated by running on the newly installed (PUMA funded)
Parsys Tandem supernode.  In particular the larger memory
and resident mass-storage capabilities should enable us to
participate in a large collaboration of European physicists
engaged on similar calculations, simulating somewhat larger
systems than we have been able to study so far.

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