Altix

Altix. The Altix was a pioneering line of high-performance computing systems developed by Silicon Graphics in the early 2000s. It represented a radical shift for the company, combining Itanium processors with a Linux-based operating system on a massively scalable ccNUMA architecture. This design enabled the creation of some of the world's most powerful supercomputers of its era, significantly impacting scientific and engineering research.

Overview

Introduced in 2003, the Altix series marked a strategic departure for Silicon Graphics from its traditional reliance on the MIPS architecture and the IRIX operating system. The systems were built around Intel's Itanium microprocessor, which was designed for enterprise and technical computing. A key innovation was the integration of SGI's proprietary NUMAlink interconnect fabric, which allowed thousands of processors to share a single, global memory address space across a ccNUMA architecture. This design philosophy was directly influenced by the company's earlier work on the Origin 2000 and Origin 3000 servers. Major installations, such as the Columbia system at NASA's Ames Research Center, demonstrated the platform's capability for tackling grand-challenge problems in fields like computational fluid dynamics and climate modeling.

Architecture

The core architectural principle of the Altix was its global shared-memory system, enabled by the NUMAlink interconnect. This technology allowed systems to scale from a few processors to over 5,000 Itanium cores while maintaining a coherent cache and memory system, a significant engineering feat. The physical architecture often utilized modular racks, or "bricks," containing compute blades, I/O modules, and interconnect routers. Memory was distributed globally but accessed uniformly, minimizing the programming complexity often associated with large-scale distributed memory systems like those using Message Passing Interface. This design placed the Altix in competition with other large-scale systems from IBM, Cray, and Hewlett-Packard, but with a distinct focus on single-system image scalability.

Operating System Support

The Altix ran a single, global instance of the Linux kernel, modified by SGI to support its unique ccNUMA architecture. This was a landmark development, proving that a commodity open-source operating system could effectively manage a system with thousands of processors and terabytes of shared memory. The Linux distribution was typically based on Red Hat Enterprise Linux or SUSE Linux Enterprise Server, providing a familiar environment for scientific users. Key enhancements included SGI's ProPack kernel extensions, which optimized performance for the NUMAlink fabric and provided advanced resource management tools. This move to Linux contrasted sharply with the proprietary UNIX environments that had previously dominated the high-end technical computing market.

Applications and Usage

Altix systems were deployed for a wide range of computationally intensive applications across government, academic, and industrial research. At NASA, the Columbia system performed simulations for the Space Shuttle program and astrophysics research. In the automotive and aerospace sectors, companies like Boeing and Airbus used them for finite element analysis and crash simulation. The systems were also pivotal in life sciences for genomics and protein folding studies, supporting research at institutions like the National Institutes of Health. The shared-memory model made them particularly well-suited for large, complex datasets that were cumbersome to partition across a clustered system, facilitating breakthroughs in quantum chemistry and materials science.

Historical Significance

The Altix is historically significant as a bridge between the era of proprietary UNIX supercomputing and the ascendance of commodity-based Linux clusters. It demonstrated that a unified Linux environment could scale to supercomputer levels, influencing the design of future large-scale systems. The project also represented the last major hardware innovation from Silicon Graphics before its decline and eventual bankruptcy filing in 2009. While the Itanium processor itself did not achieve widespread commercial success, the Altix's architectural concepts, particularly in scalable memory coherence, informed subsequent high-performance computing designs. Its legacy is evident in the continued importance of large-memory, NUMA-based nodes within modern hybrid computing architectures that combine shared and distributed memory paradigms.

Category:Supercomputers Category:Silicon Graphics hardware Category:Linux computers Category:Computer-related introductions in 2003