SANTA CLARA, Calif. -- September 7, 2004 - Sun Microsystems, Inc. (Nasdaq: SUNW) extended its leadership position in the high performance and technical computing (HPTC) market, according to the latest research from IDC. Sun maintained its number one market share position in unit shipments with 33.8 percent unit growth quarter-over-quarter (Q/Q), outpacing the overall market. Sun also extended its market share lead in shipments to 44.5 percent, nearly 18 points higher in share than its closest competitor, according to IDC's Technical QView, Q2 2004. Driven by explosive sales of Sun's AMD Opteron processor-based systems, Sun grew overall unit market share on a year-over-year (Y/Y) basis, gaining a healthy 12.2 share points.

This quarter's QView report demonstrates a maturation of the HPTC market, with a balance between strong growth in small node clusters and continued demand for large memory SMP systems. "IDC's report further validates that our product strategy is perfectly aligned with overall industry trends. As the industry continues to deploy low-cost clustered servers, Sun is rapidly fulfilling customer demand for our AMD Opteron processor-based systems on the low end. At the same time, Sun's new CMT UltraSPARC IV servers are adding serious muscle to Grid deployments on the high-end," said Larry Singer, senior vice president and strategic insights officer at Sun Microsystems, Inc. "The combination of our Opteron and SPARC based product lines, paired with our leading N1 Grid Engine software and the Solaris OS, has enabled Sun to meet the most demanding HPTC needs and help customers successfully reap the benefits of Grid computing across a spectrum of workloads."

Several notable customer wins helped drive Sun's strong performance, including a top-five financial services firm in the United States, a top-five European bank and a leading US government research facility, The Idaho National Engineering and Environmental Laboratory (INEEL).

INEEL, which is developing a high performance computing cluster for use in next-generation nuclear reactor design, will benefit from more than 230 Sun Fire V20z servers powered by AMD Opteron processors, and more than 12 Terabytes of Sun StorEdge 6320 storage, the Solaris 9 Operating System, Sun Java Enterprise System and Java development software, Sun Grid Engine Enterprise Edition, Sun's StarOffice 7.0 office productivity platform, as well as advanced on-site training and support from Sun's Services division (see related press release: http://www.sun.com/smi/Press/sunflash/2004-08/sunflash.20040812.1.html).

Additional highlights from the IDC Technical Server QView report include:

• Sun gained 12.4 unit market share points Y/Y in the departmental segment, due to growing demand for the newly introduced Sun Fire V20z server. In addition, Sun saw strong sales of the Sun Fire V60x, V65x, V210, V240 and V440 systems, enabling Sun to increase its sizable share of the segment to 45.7 percent.
  
  
• Solid sales of the Sun Fire E25K and 15K systems demonstrated continued demand for large memory SMP systems for workloads not addressed by small node clusters.
  
  
• Sun continues to hold the number one position in worldwide HPTC total unit shipments and in worldwide HPTC departmental unit shipments.
  
  
• Sun maintained its position among the top three leaders in worldwide revenue, posting 24.2 percent Y/Y growth.

Full details are listed in IDC's High Performance Technical Computer QView Report, published Sept. 1, 2004.

About Sun Microsystems, Inc.

Since its inception in 1982, a singular vision -- "The Network Is The Computer" -- has propelled Sun Microsystems, Inc. (Nasdaq: SUNW) to its position as a leading provider of industrial-strength hardware, software and services that make the Net work. Sun can be found in more than 100 countries and on the World Wide Web at http://sun.com

Sun, Sun Microsystems, the Sun logo, The Network is the Computer, Solaris, Sun Fire, N1 and Java are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. in the US and other countries. Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems, Inc.