• High-performance Networking • OpenVMS AXP System Software • Alpha AXP PC Hardware Digital Technical Journal Digital Equipment Corporation cleon cleon Volume 6 Number l Wimer 1994 Editorial jane C. Blake, Managing Editor Helen L. Patterson, Editor Kathleen M. Stetson, Editor Circulation Catherine M. Phillips, Administrator Dorothea B. Cassady, Secretary Production Terri Autieri, Production Editor Anne S. Katzeff, Typographer Peter R. Woodbury, Illustrator Advisory Boa.-d Samuel H. Fuller, Chairman !Uchard W Beane Donald Z. Harbert !Uchard]. Hollingsworth Alan G. Nemeth jean A. Proulx jeffrey H. Rudy Stan Smits Hobert M. Supnik Gayn B. Winters The Digital Technicaljournal is a refereed journal published quarterly by Digital Equipment Corporation, 30 Porter Road LJ02/Dl0, Littleton, Massachusetts 01460. Subscriptions to the journal are $40.00 (non-US $60) for four issues and $75.00 (non­ U.S. $115) for eight issues and must be prepaid in U.S. funds. Universit)' and college professors and Ph.D. students in the electrical engineering and computer science fields receive complimentary subscriptions upun request. Orders, inquiries, and address changes should be sent to the Digital Technicaljo urnal at the published-by address. Inquiries can also be sent electronically to [email protected]. COM. Single copies and back issues are available for S 16.00 each by calling DECdirect at 1-800-DJGlTAL (J-800-344-4825). Recent back issues of the journal are also available on the Internet at gatekeeper.dec.com in the directory /pub/DEC/OECinfo/DTJ. Digital employees may order subscriptiuns through Headers Choice by enrering VTX PROFILE at the system prompt. Comments on the content of any paper are welcomed and may be sent to the managing editor at the published-by or network address. Copyright© 1994 Digital Equipment Corporation . Copying without fee is permitted provided that such copies are made for use in educational instiwtions by faculty members and arc not distributed for commercial advantage. Abstracting with credit uf Digital Equipment Corporation's authorship is permitted . All rights reserved. The information in thejounwl is subject to change without notice and should not be construed as a commitmem by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may appear in the journal. ISSN 0898-901X Documentation Number EY-QOlJE-TJ The following are trademarks of Digital Equipment Corporation: ACMS, Alpha AXP, AXP, CJ, DEC, DEC Rdb for OpenV,viS AXP, DECchip, DECNIS 600, DECpc, DECstation, Digital, the DIGITAl. logo, GIGAswitch, HSC, KDM. MicroVAX, OpenVMS, OpenVMS AXP, OpenVMS VAX, RA, TA, ULTRlX, VAX, VMS, and VMSclustcr AT&T is a registered trademark of An1erican Telephone and Telegraph Company. !350 and SPICE are trademarks of the University of California at Berkeley. CR AY Y-MP is a registered trademark of Cray Research , Inc. CoverDesign Gateway 2000 is a registered trademark of Gateway 2000, Joe. The GlGAswitch �J'Stem is a high-performance Hewlett-Packard is a trademark of Hewlett-Packard Corporation. packet switch for interconnecting a variety Intel, lntel386, lntel486, and Pentium are trademarks of Intel Corporatiun. of network types and components, including Microsoft, MS-DOS, and Windows NT are registered trademarks of Microsoft Corporation. LANs, WANs, clients, servers, and members MIPS is a trademark of MIPS Computer Systems, Inc. of workstation farms. The grid on our cover Motorola is a registered trademark of Motorola, Inc. represents the crossbar switching fabric at OSF/1 is a registered trademark of Open Software Fuundation, Inc. the core of the GlGAswitch system. Data repre­ PAL is a registered trademark of Advanced Micro Devices, Inc. sented bere as flowing through the crossbar SPEC, SPECfp, SPECint, and SPECmark are registered trademarks of the Standard -numeric, audio, video, text-is typical of Performance Evaluation Council. applications that use the G!GAswitch system. TPC-A is a trademark of the Transaction Processing Performance Council. UNIX is a registered trademark of Unix System Laboratories, Inc. , a wholly owned The cover was designed by joe Pozerycki,]r:, subsidiary of Novell, Inc. of Digital's Corporate Design Group. J3ookproduction was clone by Quantic Communicatiuns, Inc. I Contents High-performance Networking 9 GIGAswitch System: A High-performance Packet-switching Platform Robert). Souza, P G. Krishnakumar, Ci.ineyt M. 6zveren, Robert). Simcoe, Barry A. Spinney, Robert E. Thomas, and Robert ,I. Wa lsh OpenVMS AXP System Software 23 Peiformance of DEC Rdb Version 6.0on AXP Systems Lucien A. Dimino, Rabah Mediouni, T. K. Rengarajan, Michael S. Rubino, and Peter M. Spiro 36 Improving Process to Increase Productivity While Assuring Quality: A Case Study of the Volume Shadowing Port to OpenVMS AXP Wil liam L. Goleman, Robert G. Thomson, and Paul). Houl ihan AlphaAXP PC Hardware 54 The Evolution of the Alpha AXP PC David G. Conroy, Thomas E. Kopec, and joseph R. Falcone 66 Digital's DECchip 21066: The First Cost-focused Alpha AXP Chip Dina L. McKinney, Masooma Bhaiwala, Kwong-Tak A. Chui, Christopher L. Houghton, James R. Mullens, Daniel L. Leibholz, Sanjay). Patel, De Ivan A. Ramey, and Mark B. Rosenbluth I Editor�s Introduction Notable among performance results was a world record for transactions per second in a test of the Rdb version 6.0 database running on a DEC 10000 AXP system. Data availability is another important charac­ teristic of high-end systems. Volume shadowing is a feature of the OpenVMS operating system that increases availability by rep I icating data on disk storage devices. The port of Volume Shadowing Phase II to OpenVMS AXP is a case study of how a small engineering team can use software develop­ ment processes to tackle complex system design Jane C. Blake tasks and deliver improved quality products on Ma naging Editor accelerated first-release schedules. Bill Goleman, Robert Thomson, and Paul Houlihan describe key In answer to a recent jo urnal survey question, half process innovations, including early code inspec­ of those who responded said they would like to see tions and profile testing, which simulates complex a variety of topics in each issue; half prefer the single­ scenarios in order to reveal errors. topic format. This issue of the Digital Te chnical In the first of two papers on Alpha AXP PC prod­ jo urnal will please those who like variety. The ucts, Dave Conroy, To m Kopec, and Joe Falcone papers herein address networking, database perfor­ trace the design choices, alternatives, and method­ mance, software processes, PCs, and chips. In the ology used in the evolutionary development of the fu ture, we will try to please readers on both sides first AXP PCs. The authors explore the lessons of the question by presenting single-topic issues, learned from designing two experimental systems; such as Wo rkflow Software upcoming, and issues the first demonstrated the feasibility of building that encompass a range of topics. a PC utilizing the DECchip 21064 microprocessor Our opening paper is about the GJGAswitch ami industry-standard components; the subsequent packet-switching system, used to increase data system incorporated the EISA bus. They then review transfer among interconnected LANs and in work­ the design of the DECpc AXP 150 product, which station farms. At 6.25 million connections per sec­ built on the successes of the experimental systems ond, GIGAswitch is among the industry's fastest and was completed in just 12 weeks. multipart packet-switching systems. The paper by Future Alpha AXP PCs and desktop systems will Bob Souza, P G. Krishnakumar, Ci.ineyt Ozveren, use new Alpha AXP microprocessors that have Bob Simcoe, Barry Spinney, Bob Thomas, and Bob higher levels of system integration fo r performance Wa lsh is a substantive overview of GIGAswitch, the yet employ packaging and clocking techniques first implementation of which includes an FDDI that reduce system cost. Dina McKinney, Masooma bridge. The authors discuss the major design issues, Bhaiwala, Kwong Chui, Chris Houghton, Jim including the data link independent crossbar, the Mullens, Dan Leibholz, Sanjay Patel, Del Ramey, and arbitration algorithm (called take-a-ticket), and Mark Rosenbluth explain the trade-offs and results the techniques used to ensure the robustness, relia­ of the 21066 design, which is the first microproces­ bility, and cost-effectiveness of the switch. sor to integrate a PCJ bus controller along with just as critical as network perfo rmance in high­ many other system-level functions. end system environments, such as stock exchanges At the close of this issue, we have listeel the refer­ and banking, is the performance of server-based ees who offered their expert advice on the content database management systems. In their paper on and readability of papers submitted to thejournal the DEC Rdb version 6.0 database, Lou Dimino, between January 1993 and February 1994. We are Rabah Mediouni, T K. Rengarajan, MikeRubino, and grateful fo r the specialized knowledge they have Peter Spiro examine earlier steps taken to establish shared with authors and editors alike. good database perfo rmance on AXP systems and compare these and traditional approaches with the new enhancements that shorten the code paths, minimize 1/0 operations, and reduce stall times. 2 Biographies I Masooma Bhaiwala A hardware engineer in the Models, To ols, and Verifica­ tion Group of Semiconductor Engineering, Masooma Bhaiwala has contributed to several projects since joining Digital in 1991 . She worked on the 1/0 controller verification of the DECchip 21066 microprocessor and wrote the PC! transactor that mimics Intel's PC! bus protocol. Recently, she led the DECchip 21066 second­ pass verification efforts. Masooma received a B.S.C.E. from N.E.D. University of Engineering and Technology, Pakistan, and an M.S.C.E. from the University of Massachusetts at Lowell. Kwong-Tak A. Chui Kwong Chui, a principal engineer in the Semiconductor Engineering Group, is currently leading the definition of a core chip set for a ruse processor.