IRIX Runs Multi-User on Eight Processors and Four Nodes of an Emulated SGI Origin 2000

The Largest SGI Machine the Project Has Booted Reaches a Login on Fifteen Consecutive Cold Starts and Passes the Vendor’s Field Diagnostics

THE MACHINE ROOM (September 14, 2026). The Origami project today announced that IRIX 6.5.30m boots to a multiuser root console on an emulated SGI Origin 2000 with eight R10000-class processors across four cache-coherent nodes, and reaches that login on fifteen consecutive cold starts once its reliability defects were fixed. The Origin 2000 is SGI’s 1996 MIPS/IRIX ccNUMA server, and four nodes behind its router fabric is the largest configuration of the machine this project has carried to a running operating system.

The machine is -M origin2000: four SN0 nodes, each a pair of 180 MHz R10000-class processors with its own Hub node controller, joined by two Crossbows and two NUMAlink routers into a single 256 MB cache-coherent module. The base I/O chip carries the serial console, the Ethernet and the SCSI. The emulated Origin 200 the project reached earlier this year is a one- and two-node machine. This is eight processors on four nodes behind the full crossbar and router fabric, the topology the Origin line was built around.

The Firmware Counts Eight Processors and Four Nodes

The stock PROM discovers the machine, walks its NUMAlink fabric, and hands off to IRIX without a complaint about the hardware it finds. Its own power-on configuration summary reads:

No. of NODEs enabled    = 4
No. of CPUs enabled     = 8
Mem enabled             = 256 MB
No. of RTRs enabled     = 2

The firmware finds six objects on the fabric, four Hubs and two routers, elects a global master among them, and reports “8 CPUs on 4 nodes found” before the operating system starts. IRIX then brings up all eight processors and reaches a multiuser root console.

Passing the Diagnostics SGI Shipped

From that console the machine runs SGI’s own field diagnostic suite, the programs the vendor wrote to qualify Origin hardware on the factory floor and in the field. The disk exerciser oldisk, the peripheral test olperi, the NUMAlink linktest, all five sections of the memory exerciser olmem, and the processor tests torpedo, pandora and olvst each complete and pass. Every diagnostic whose hardware the run provides passes: the machine runs the programs SGI wrote to qualify Origin hardware and comes through them without a miscompare.

Reliable Across Cold Starts

The eight-processor login is repeatable, not a single lucky boot. Three defects that had been costing whole processors or whole nodes on a fraction of cold starts were found, fixed and pinned with register-level tests, all on the project’s main line. With them in place, the machine reached a multiuser login on fifteen consecutive cold starts, every one bringing up the full complement of eight processors.

About This Project

Origami is a permanent fork of QEMU that emulates SGI’s MIPS/IRIX ccNUMA machines. It exists because nothing else emulated them, and because SGI’s firmware, IRIX and field diagnostics are the strongest available witness that the model is faithful. It ships nothing and sells nothing. It is a research and preservation project, unaffiliated with Silicon Graphics.

SGI, IRIX, Origin, MIPS, R10000 and NUMAlink are trademarks of their respective owners, and this project is unaffiliated with any of them. No SGI code is reproduced in the fork.