🚀 go-pugleaf

Digital Technical Journal -- Volume 6, Number 2

EDITOR'S INTRODUCTION

Jane C. Blake, Managing Editor

This issue of the Digital Technical Journal presents papers from three
companies -- Cray Research, Raytheon, and Kubota Graphics -- that have
developed high-performance systems based on the Alpha AXP 64-bit
microprocessor. Also included here are papers about the Alpha AXP chip sets
for building PCI-based systems and on the compression technique used in the
DLT2000 tape product.

Cray Research, the parallel vector processor and supercomputing pioneer,
has developed its first massively parallel processor (MPP) for customers
who seek the price/performance advantages of an MPP design. As Kent
Koeninger, Mark Furtney, and Martin Walker explain, Cray's MPP uses
hundreds of fast commercial microprocessors, in this case Digital's DECchip
21064; whereas a parallel vector processor uses dozens of custom (more
expensive) vector processors. Their paper focuses on the CRAY T3D system --
an MPP designed to enable a wide range of applications to sustain
performance levels higher than those attained on parallel vector
processors. The authors review major system aspects, including the
programming model, the 3-D torus interconnect, and the physically
distributed, logically shared memory.

For the U.S. military, Raytheon has designed an extended environment,
commercial off-the-shelf (E2COTS) computer based on the DECchip 21066/68
AXPvme 64 board. Bob Couranz discusses the characteristics of the E2COTS
board that provide the military with cost and performance advantages. He
describes how designers addressed the military's reliability requirements,
one of which is computer operation in a wide temperature range of -54
degrees C to 85 degrees C. Packaging modifications made by Raytheon include
reconfiguration of the module board for conduction cooling as opposed to
the convection cooling of the commercial product.

Kubota Graphics' advanced 3D imaging and graphics accelerator is used in
Digital's DEC 3000 Alpha AXP workstations and in Kubota's workstations. Ron
Levine's paper interweaves a description of the Kubota accelerator product
with a tutorial on imaging, graphics, and volume rendering. He begins by
distinguishing between imaging and graphics technologies and their
relationship to volume rendering methods. He then reviews application
areas, such as medical imaging and seismic exploration, and expands on
volume rendering techniques. The final section addresses the Kubota
implementation, the first desktop-level system to provide interactive
volume rendering.

Digital encourages broad industry application of the Alpha AXP family of
microprocessors. Sam Nadkarni, Walker Anderson, Lauren Carlson, Dave
Kravitz, Mitch Norcross, and Tom Wenners describe the chip sets -- one cost
focused and one performance focused -- system designers can use to easily
build PCI-based Alpha AXP 21064 systems. The authors also present an
overview of the EB64+ evaluation kit. This companion to the chip sets gives
designers sample designs and an evaluation platform which allows them to
quickly evaluate the cost and performance implications of their design
choices.

The state-of-the-art DLT2000 tape drive offers high data throughput, up to
3M bytes/s, and  high data capacity, up to 30G bytes (compressed). David
Cressman outlines the product issues that drove the DLT2000 development and
then details the developers' investigation of the performance impact to the
tape drive design of two different data compression algorithms, the
Lempel-Ziv algorithm and the Improved Data Recording Capability (IDRC)
algorithm. He reviews the tests conducted to measure compression efficiency
and data throughput rates. The test results, unexpected by developers,
reveal that the design using Lempel-Ziv compression generally achieves
higher storage capacity and data throughput rates than the IDRC-based
design.

=============================================================================
Copyright 1994 Digital Equipment Corporation.  Forwarding and copying of this
article is permitted for personal and educational purposes without fee
provided that Digital Equipment Corporation's copyright is retained with the
article and that the content is not modified. This article is not to be
distributed for commercial advantage. Abstracting with credit of Digital
Equipment Corporation's authorship is permitted.  All rights reserved.
=============================================================================