For the rack variant, see the Origin 2000 article

A late era Onyx2 with the later 'sgi' logo
A late era Onyx2 with the later 'sgi' logo

The SGI Onyx2, code name Kego, is the successor of the SGI Onyx. The Onyx2's basic system architecture is based on the Origin 2000, but the midplane and some parts such as the IO6 are different between models. The Onyx2 is notable for the InfiniteReality2, 2E and 3 boards it usually is equipped with, as well as its imposing size, weight and aesthetics.


The Onyx2 deskside form factor can handle up to 4 CPUs distributed across two nodeboards, a maximum of 4 GB of RAM, one GE-16-4, a single DG5-8 for up to 8 displays, and two IR3 or IR4 raster managers for a maximum of 512 MB and 2 GB respectively of texture memory, and can support up to two users simultaneously out of the box. Possibly more with a CADDUO card installed.

A 3-slot PCI cage can be installed as well as a maximum of 10 XIO cards, giving a massive amount of expandability. This is in addition to 5 hard disks and one 5.25 option drive.


The following table shows the possible CPU configurations.

Processor Clockspeed Cache
R10000 180 MHz 1MB R10000
R10000 195 MHz 4MB R10000
R10000 250 MHz 4MB R10000
R12000 300 MHz 8MB R12000
R12000 350 MHz 4MB R12000
R12000 400 MHz 8MB R12000
R14000 500 MHz 8MB R12000


The Onyx2 can handle the following revisions of the InfiniteReality:

Model GE Revision Raster Manager Display Generator Texture RAM (MB) Raster RAM (MB)
InfiniteReality2 GE14-4 RM7-16 or RM7-64 DG5-2 or DG5-8 16 to 32 80 to 160
Reality GE14-2 RM8-16 or RM8-64 DG5-2 or DG5-8 16 to 64 40 to 80
InfiniteReality2E GE16-4 RM9-64 DG5-2 or DG5-8 64 to 128 80 to 160
InfiniteReality3 GE16-4 RM10-256 DG5-2 or DG5-8 256 to 512 80 to 160
InfiniteReality4 GE16-4 RM11-1024 DG5-2 or DG5-8 1,024 to 2048 2,560 to 5,120
An early model Onyx2 with the old SGI logo and skin
An early model Onyx2 with the old SGI logo and skin

InfiniteReality2 is how hinv refers to an InfiniteReality that is used in the Onyx2. The InfiniteReality2 however, was still marketed as the InfiniteReality. It is the second implementation of the InfiniteReality architecture, and was introduced in late 1996. It is identical to the InfiniteReality architecturally, but differs mechanically as the Onyx2's Origin 2000-based card cage is different from the Onyx's Challenge-based card cage.

The Reality is a cost-reduced version of the InfiniteReality2 intended to provide similar performance. Instead of using the GE14-4 Geometry Engine board and the RM7-16 or RM7-64 Raster Manager boards, the Reality uses the GE14-2 Geometry Engine board and the RM8-16 or RM8-64 Raster Manager boards. The GE14-2 has two Geometry Engine Processors, instead of four like the other models. The RM8-16 and RM864 has 16 or 64 MB of texture memory respectively and 40 MB of raster memory. The Reality was also limited by the number of Raster Manager boards it could support, one or two. When maximally configured with two RM8-64 Raster Manager boards, the Reality pipeline has 80 MB of raster memory.

The InfiniteReality2E is an upgrade of the InfiniteReality, marketed as the InfiniteReality2, introduced in 1998. It succeeded the InfiniteReality board set and was itself succeeded by the InfiniteReality3 in 2000, but was not discontinued until 10 April 2001.

It improves upon the InfiniteReality by replacing the GE14-4 Geometry Engine board with the GE16-4 Geometry Engine board and the RM7-16 or RM7-64 Raster Manager boards with the RM9-64 Raster Manager board. The new Geometry Engine board operated at 112 MHz, improving geometry and image processing performance. The new Raster Manager board operated at 72 MHz, improving anti-aliased pixel fill performance.

InfiniteReality3 is the next upgrade and one of the most common for the Onyx2 and Onyx3000 on the secondhand market. The only improvement over the previous implementation is replacement of the RM9-64 Raster Manager with the RM10-256 Raster Manager, which has 256 MB of texture memory, four times that of the previous raster manager.

InfiniteReality4 is the ultimate iteration, introduced in 2002. Primarily used on the Onyx3000 and Onyx350 "G-Bricks". The only improvement over the previous implementation is the replacement of the RM10-256 Raster Manager by the RM11-1024 Raster Manager, which has improved performance, 1 GB of texture memory and 2.5 GB of raster memory, four and thirty-two times that of the previous raster manager, respectively.

Below is a performance table offering comparisons:

Reality 5.5 94 to 188 100 to 200
InfiniteReality2E 13.1 to 210 192 to 6,100 200 to 6,400
InfiniteReality3 13.1 to 210 5,600 6,400
InfiniteReality4 13.1 to 210 10,200 6,400
The rear of the system, minimally configured.
The rear of the system, minimally configured.


DIMMs are available in sizes of 16, 32, 64 and 256 MB. The memory modules used in the Origin 200 and Origin 2000 / Onyx 2 are of the same type. To support the Origin 2000 distributed shared memory model, the memory modules are proprietary and include directory memory, which contains information on the contents of remote caches for maintaining cache coherency, supporting up to 32 processors. Additional directory memory is required in configurations with more than 32 processors. The additional directory memory is contained on proprietary DIMMs that are inserted into eight DIMM slots set aside for its use.


An IO6G base I/O board is present in every system. It is a XIO card that provides:

  • a 10/100BASE-TX Ethernet port
  • 2 sets of PS/2 ports
  • 4 Serial ports provided by dual UARTs
  • 1 internal Fast 20 UltraSCSI single-ended port
  • 1 external wide UltraSCSI, singled ended port
  • 1 real-time interrupt output for frame sync
  • 1 real-time interrupt input (edge triggered)

Also on the card is the Flash PROM, NVRAM and real time clock of the system.


The system can utilize PCI with the addition of an Origin 2000 XIO PCI "Shoebox" or individual XTalk PCI adapters inserted in the cage. These are the same sort form factor as Octane units.

Operating System Support

IRIX Versions from 6.4 to 6.5.30 supported the Onyx2