SGI Indigo² and Challenge M

The SGI Indigo² and the SGI Challenge M were Unix computers marketed by SGI from 1992 to 1997.

The Indigo², code named Fullhouse, was a desktop workstation. The Challenge M was a server which differed from the Indigo² only by a slightly differently colored and badged case, and the absence of graphics and sound hardware. Both systems were based on the MIPS processors. Both systems supported EISA bus and SGI proprietary GIO64 expansion bus via a riser card.

SGI Indigo² workstation is a direct successor to the SGI Indigo model. Until the introduction of SGI Octane, SGI Indigo² was SGI's most powerful desktop system for 3D, visualization and high performance computing environments.

Introduction

SGI Indigo² desktop workstations had two models: the teal case Indigo² - earlier model (original concept), and the later - often called IMPACT model - with purple colored case. Both looked the same from outside except color, and sub-model case badging. The available CPU types, the amount of RAM and GFX capabilities depends on the model or sub-model variation. There was a special version of the "Teal" Indigo², called Power Indigo²; this system had increased FPU (floating point unit) capabilities and used specially designed R8000 CPUs. It's natural that later IMPACT Indigo² workstation model gives more computational and visualization power, especially due to the introduction of R10000 series RISC CPU, and IMPACT graphics.

SGI Indigo

The Indigo, introduced as the IRIS Indigo, is a line of workstation computers developed and manufactured by Silicon Graphics, Inc. (SGI). SGI first announced the system in July 1991.

The Indigo is considered one of the most capable graphics workstations of its era, and was essentially peerless in the realm of hardware-accelerated three-dimensional graphics rendering. For use as a graphics workstation, the Indigo was equipped with a two-dimensional framebuffer or, for use as a 3D graphics workstation, with the Elan graphics subsystem including one to four Geometry Engines (GEs). SGI sold a server version with no video adapter.

The Indigo is a visually pleasing design, based on a simple cube motif in indigo hue. Graphics and other peripheral expansions were accomplished via the GIO32 expansion bus.

The Indigo was superseded generally by the SGI Indigo2 (and in the low-cost market segment by the SGI Indy), although Indigo remained useful among some specialties even into the 2000s.