Press Release

Raytheon Selects Dual-Core SGI Altix 4700 Systems for NOAA R&D Contract

Powered by Dual-Core Intel Itanium 2 Processors, Altix Systems to Drive Large-Scale Processing of Data-Rich Climate Codes

MOUNTAIN VIEW, Calif. (July 18, 2006)—Silicon Graphics, Inc. (OTC: SGID) today announced that Raytheon Company has selected a range of large-scale SGI® Altix® 4700 systems as computational resources to run mathematical models and computer simulations to help better understand global climate change.

The new SGI systems are powered by a total of 1,280 Dual-Core Intel® Itanium® 2 processor 9000 series CPUs (formerly codenamed Montecito) and 5.1TB of globally shared memory.

Raytheon selected two 768-core (or 384-processor) Altix 4700 systems and a 1,024-core (or 512-processor) Altix 4700 system. All systems are scheduled for deployment this October as part of an existing contract between Raytheon and the National Oceanic and Atmospheric Administration (NOAA) research and development (R&D) high-performance computing system contract to maintain, operate and upgrade high performance computing platforms.

Running SUSE® Linux Enterprise Server 9 from Novell, the new systems will serve as large, shared-memory platforms for processing data-rich climate codes that can require up to 500 processors for a single job. The complex models are used to understand the physical processes that may determine global climate changes, and to forecast hurricane tracks.

The dual-core Altix 4700 systems will be integrated within an existing SGI high-performance computing (HPC) environment, which consists of single-core Altix systems driven by 2,656 Intel® Itanium® 2 processors and more than 5 Petabytes of online tape storage managed by SGI® InfiniteStorage Data Migration Facility (DMF). Data for long climate studies is moved off of tape for processing by DMF to a Storage Area Network featuring SGI® InfiniteStorage Shared Filesystem CXFS™.

SGI announced its dual-core Altix 4700 systems in June. (See "SGI Launches New Mid-Range Altix 450 Servers and Doubles Performance of Altix 4700 Blades"). Ideal for HPC environments with demanding data-intensive workloads, the dual-core Altix 4700 system scales from 8 to 512 CPU sockets (up to 1,024 processor cores) and can accommodate up to 6TB of globally shared memory in a single system while delivering a teraflop of performance in a small-footprint rack.

Pricing and Availability
SGI Altix 4700 systems are expected to be available in late August of 2006. Altix 4700 system configurations start at less than $75,000. For more information, visit: http://www.sgi.com/products/servers/altix/4000/.

SILICON GRAPHICS | The Source of Innovation and Discovery™
SGI, also known as Silicon Graphics, Inc. (OTC: SGID), is a leader in high-performance computing. SGI helps customers solve their computing challenges, whether it's sharing images to aid in brain surgery, designing and manufacturing safer and more efficient cars and airplanes, studying global climate, providing technologies for homeland security and defense, enabling the transition from analog to digital broadcasting, or helping enterprises manage large data. With offices worldwide, the company is headquartered in Mountain View, Calif., and can be found on the Web at www.sgi.com.

Silicon Graphics, SGI, Altix, the SGI cube and the SGI logo are registered trademarks and CXFS and The Source of Innovation and Discovery are trademarks of Silicon Graphics, Inc., in the United States and/or other countries worldwide. Linux is a registered trademark of Linus Torvalds in several countries. Intel and Itanium are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. Novell and SUSE are registered trademarks of Novell, Inc. in the United States and other countries. All other trademarks mentioned herein are the property of their respective owners.

This news release contains forward-looking statements regarding SGI technologies and third-party technologies that are subject to risks and uncertainties. These risks and uncertainties could cause actual results to differ materially from those described in such statements. The reader is cautioned not to rely unduly on these forward-looking statements, which are not a guarantee of future or current performance. Such risks and uncertainties include long-term program commitments, the performance of third parties, the sustained performance of current and future products, financing risks, the ability to integrate and support a complex technology solution involving multiple providers and users, and other risks detailed from time to time in the company's most recent SEC reports, including its reports on Form 10-K and Form 10-Q.