SGI Octane
| Company type | Workstation line |
|---|---|
| Industry | Computer hardware |
| Predecessor | Indigo2 |
| Founded | 1997 |
| Successor | Tezro |
Area served | Worldwide |
| Products | Octane, Octane2, Octane III workstations |
| Parent | Silicon Graphics, Inc. (SGI) |
The Octane line of IRIX workstations was produced and marketed by SGI in the late 1990s through the early 2000s. Both the Octane and Octane2 models are dual-processor multiprocessing workstations originally designed around the MIPS Technologies R10000 CPU, with subsequent versions incorporating the R12000 and R14000 processors. The Octane2 brought several upgrades such as a redesigned power supply, an updated system board, an enhanced Xbow ASIC, and support for VPro graphics. Some later iterations of the original Octane adopted these improvements from the Octane2. Their respective codenames were "Racer" for the Octane and "Speedracer" for the Octane2.
Serving as the direct replacement for the Indigo2, the Octane was later succeeded by the Tezro, while the O2 was released as a contemporaneous counterpart. SGI discontinued sales of the Octane2 on May 26, 2004, halted manufacturing a month afterward, and ended official support in June 2009.
After SGI’s bankruptcy reorganization, the Octane III was introduced in early 2010 as an Intel-based workstation series featuring Xeon processors in deskside chassis, along with cluster servers capable of housing up to ten system trays filled with Twin Blade or Intel Atom Mini-ITX nodes.
Hardware
The Octane’s motherboard, known as IP30, is constructed around SGI’s Xtalk architecture that replaces a conventional system bus with a Crossbow ASIC (Xbow). This Xbow functions as a dynamic crossbar switch connecting multiple XIO ports to a central hub. One port links to the CPU and memory subsystem, another provides a PCI-X expansion interface, and four high-speed XIO slots serve as high-bandwidth connections—similar to a single node within the Origin 200 architecture.
Bridging between XIO and PCI-X is achieved through a BRIDGE chip, which enables attachment of components such as the IOC3 multi-I/O controller, ISP1040B SCSI adapters, RAD1 audio integrated on the motherboard, MENET cards (each containing four IOC3 chips), and PCI cards installed within the PCI cage. The Octane utilizes ARCS boot firmware consistent with other SGI platforms from its time period.
CPUs
Available processors for the Octane series include:
| Processor: | Cache: | Single (MHz): | Dual (MHz): |
|---|---|---|---|
| R10000SC | 1 MB | 175, 195, 225, 250 | 175, 195, 225, 250 |
| R12000SC | 2 MB | 270, 300, 400 | 270, 300, 400 |
| R12000SCA | 2 MB | 360, 400 | 360, 400 |
| R14000SCA | 2 MB | 550, 600 | 550, 600 |
The series supports both single-CPU and dual-CPU configurations; however, adding a second processor requires swapping out the entire CPU module.
Memory
System memory capacity ranges from 64 MB up to 8 GB using up to eight proprietary 200-pin DIMM modules. There are two versions of the motherboard: an earlier revision supporting a maximum of 2 GB RAM and a later one capable of handling up to 8 GB. The HEART memory controller connects the processor, SDRAM, and XIO bus directly through the Xbow router to any attached XIO device while providing substantial bandwidth.
Graphics
Graphics capabilities on the Octane are delivered via multiple card options: SI, SI+T, SSI, MXI—these are upgraded XIO variants of Solid Impact (SI), High Impact (SI+T), and Maximum Impact (MXI) graphics originally from the SGI Indigo2, internally referred to as 'MARDIGRAS'. These cards were further enhanced with accelerated geometry pipelines and texture mapping units into SE, SE+T, SSE, and MXE models. The SI/SE cards feature a framebuffer size of 13.5 MB; SSE and MXE models double that to 27 MB.
The '+T' suffix indicates an additional high-speed RDRAM texture board containing 4 MB of texture memory—SI/SE+T cards include one such board; MXI/MXE cards have two boards which double texture throughput but not total texture memory capacity.
Later versions of both Octane and Octane2 support SGI’s VPro 'ODYSSEY' graphics family. Initial VPro models were V6 (32 MB RAM) and V8 (128 MB RAM), followed by V10 (32 MB) and V12 (128 MB) which offered twice the geometry processing performance compared to their predecessors. The V6/V10 allocate up to 8 MB for textures; V8/V12 provide up to 108 MB.
The VPro graphics subsystem incorporates SGI’s proprietary chipset including the buzz ASIC—a single-chip graphics pipeline running at 251 MHz featuring on-chip SRAM—and pixel blaster & jammer (PB&J) ASICs. Communication with the host is via a peer-to-peer XIO link operating at 16 bits and 400 MHz. Depending on model configuration, SDRAM capacity is either 32 or 128 MB.
All VPro graphics boards support OpenGL, having upgraded from MARDIGRAS's OpenGL version 1.1 plus SGI Extensions to OpenGL version 1.2 along with OpenGL ARB imaging extensions that provide hardware-accelerated real-time image processing operations.
IMPACT Series
| Variant | Enhanced Variant | Framebuffer Size | Geometry Processors | Rasterization Units | Texture Units |
|---|---|---|---|---|---|
| SI | SE | 13.5 MB | 1 | 1 | none |
| SI+T | SE+T | 13.5 MB | 1 | 1 | 1 (4 MB) |
| SSI | SSE | 27 MB | 2 | 2 | none |
| MXI | MXE | 27 MB | 2 | 2 | 2 (4 MB) |
VPro Series
| Model | Colour Precision | Memory Capacity | Maximum Texture Memory | Geometry Processing Speed |
|---|---|---|---|---|
| V6 | 48-bit RGBA | 32 MB | 8 MB | Standard speed |
| V8 | 48-bit RGBA | 128 MB | 104 MB | Standard speed |
| V10 | 48-bit RGBA | 32 MB | 8 MB | Double standard speed |
| V12 | 48-bit RGBA | 128 MB | 104 MB | Double standard speed |
Audio
The standard audio components provide low-latency streaming with approximately 3 ms delay from input to output. Integrated connectors include an 8-channel, 24-bit Alesis ADAT optical interface, along with S/PDIF and AES/EBU in both optical and coaxial forms.
Case
Octane chassis dimensions are 30 by 40 by 35 centimeters, with a weight of 25 kilograms. These cases do not feature internal bays for 5.25" drives, necessitating the use of external CD-ROM units. Expansion capabilities encompass video and audio input/output, networking interfaces, real-time video compression cards, and external storage connectivity through SCSI, Fiber Channel, or FireWire. Standard PCI expansion cards can be installed using an optional PCI cardcage or a PCI-to-XIO adapter commonly referred to as a 'shoehorn.' Upgrading to VPro graphics on earlier Octane models is feasible; however, V10 and V12 cards require Xbow revision 1.4 combined with Cherokee power supplies, whereas V6 and V8 cards depend on Xbow revision 1.3 and Cherokee power.
Regarding aesthetics, the original Octane features a green exterior adorned with the SGI 'cube' emblem. Subsequent versions retain this green color but adopt branding consistent with Octane2 styling. The Octane2 models present a blue casing accompanied by a lowercase SGI logo.
I/O subsystem
The Octane platform is equipped with two SCSI controllers that support Ultra Wide SCSI devices. It can house up to three internal 3.5" SCSI SCA hard drives mounted on proprietary sleds compatible across Origin 2000, Origin 200, and Onyx2 systems. Additionally, an external Ultra Wide SCSI port allows attachment of further peripherals.
Operating systems
Support for IMPACT-class graphics was introduced starting with IRIX version 6.4. For VPro-class graphics, compatibility began with IRIX 6.5.10 for the V6 and V8 variants, while V10 and V12 models received support from version 6.5.11 onward (or 6.5.10 when applying an update). The Octane architecture is also supported by Linux and OpenBSD operating systems.