For my fourth and last Silicon Graphics computer, I really wanted an Octane! Voilà chose faite ! I’ve waited long enough to snatch the right system when I found it. My requirements were high: a working machine, loaded with HW features, in great cosmetic condition and cheap. I almost forgot I was looking for the original Octane (not the Octane2). After a few years, I finally scored a couple of weeks ago this elusive SGI on my want list. The first surprise when I had to pick it up: this desk-site workstation weight a ton (~54 lbs. / 25 kg to be precise – 30 x 40 x 35 cm). My Octane has two processors (MIPS R12000 IP30 [32KB Instructions and Data caches] with MIPS R12010 FPUs) paced at 300 MHz. This may seem low compared to PCs of the same era (1997), but performance-wise, it is a day and night situation.
Better Than a PC
As we will see it later, the Octane has an extremely well-designed system architecture that scales! So, every major HW node of the workstation works at its nominal performance, especially the CPUs. Therefore, a 300 MHz CPU is never waiting – at least in comparison to a PC processor – on nodes such as the memory of the graphics. That’s what differentiated a PC from a UNIX Workstation! With 2 GB of RAM and three 32GB SCSI HDDs (two UW SCSI QLogic 1040B controllers), the machine is at the top of the range. It is equipped with three graphic cards (Mardi Gras) allowing for a triple-monitor configuration (one IMPACTSR v2 [RA v0, HQ vB, GE11 vB, RE4 vC, PP1 vA, VC3 vA, CMAP vE, Heart vF], and two IMPACTSR v1). Note that it is hard to remove the Octane’s heatsinks without risking damaging the processors/ASICs.
An XBar at its HEART
This is the reason why the board pictures are exhibiting very large heatsinks. Sorry, I do not want the take chances :). At the heart of the Octane, there is a high-bandwidth crossbar (XBar) using a packet-based protocol. In the short, each node connected to the XBar can communicate with each other at full bandwidth. Well, that definitively contribute to the performance gap with basic PCs. A total of four XIO slots are available to connect the system’s various nodes. Unfortunately, my Octane didn’t come with a PCI expansion box, so I cannot add, using the PCI-64 bridge, up to three PCI boards. From a physical point of view, the Octane is modular and the CPU/Memory, Graphics, IO, etc. nodes are implemented as boards. Each board slides in the chassis and connects to the baseboard located in the front. You can clearly see the XIO connectors in the photos. As usual, the build quality of the Octane is excellent. And it worth signaling that the Cherokee PSU (~800 W) is still working great after 20 years, making the system silent enough to consider using it next to my desk. And if you wonder which OS runs the Octane: it is the SGI proprietary 64-bit UNIX, IRIX 6.5.