I love the Origin 200. For the form factor, it just can’t be beaten – lots of storage capacity with decent processing power and immense I/O. More than that, the underlying technology is deeply impressive. Silicon Graphics at it’s finest.

At today’s prices, and given the modular nature of the O200, it is unbeatable in terms of price/performance.

All Origin 200 units (Origin 200, Origin GIGAChannel, Origin Vault) are available as either a tower or a 19" rack mount chassis. The tower skins can be easily removed to make a chassis rack mountable – conversely you can add tower skins to a rackmount box to make it a free standing tower.

They’re very flexible machines – this modularity of design has been carried on in the Origin 300/350 and Altix 350.

CPUs

Each O200 can have 1 or 2 CPUs. Like the Octane, these are either single or dual modules. As the O200 and the Octane are based on the same Origin 2000 technology, the CPU choices are very similar.

RAM

Each O200 can have from 32MB to 2GB RAM fitted. There are 8 DIMM slots, arranged in 4 banks. DIMMs must be fitted in pairs in each bank.

Bank 0 must be fully populated for the machine to boot.

Storage

Each Origin 200 has 2 5.25" bays, with 50pin 20mb/s SCSI connections. They also have 6 3.5" hot plug bays, which use SCA connectors, and plug into a 40mb/s SCSI bus.

The 5.25" bays don’t require any special mounting kits – the assembly is removed and the drives can be screwed in on either side.

The 3.5" bays require drive sleds – these are the same as on the Octane. There are no limits on drive capacity. Due the depth limits on the sleds you will not be able to fit non-SCA drives with adapters – you must use 80pin SCA drives. However, due to the backwards compatible nature of SCSI, the latest LVD high speed SCA drives will still work in an O200.

Origin Vault

Getting more use out of the Origin 200 chassis, there is the Origin Vault. This provides 6 3.5" SCA drive bays on a differential SCSI bus, and 2 5.25" drive bays on a SE SCSI bus.

To use both busses, you will need to have 2 connections to your host chassis:

• one to a differential SCSI card (either XIO from a GIGAChannel, or a PCI card in either GIGAChannel or an O200)
• one to an SE SCSI card (XIO, PCI, or on-board SCSI)

Craylink

Craylink on the Origin 200 is the same as NUMAlink on the Origin 2000. The only difference is that it is limited to 2 nodes on the O200. It provides a 1.15GB/s connection between two O200s, giving you a 2 or 4 way NUMA machine. To expand to another chassis, all you need to do is open the case on the 2nd machine, change the DIP switches above the drive bays so that it is a slave node, then connected the two chassis together with a Craylink cable, and power them on.

During the POST the master chassis will probe the Craylink interface, and configure the machine up with the resources of both chassis. Although you had two physically seperate O200s, when Craylinked together, they become one single system image machine, with the resources of both chassis fully available to IRIX.

GIGAChannel

The GIGAChannel expansion box is basically an O200 chassis with the normal drive bays at the front. However, inside it has 5 XIO slots and 4 64bit PCI slots.

GIGAChannel plugs into an XIO adapter daughter board – these fit just above the Craylink connectors on the main motherboard.

Each O200 can have 1 GIGAChannel connected to it – this means the max configuration is 2 O200 towers, each with their own GIGAChannels.

Maximum Configuration

One of the best strengths is the scalability of the Origin 200. In the maximum configuration possible, you would have 4 chassis:

• 1 master CPU unit
• 1 slave CPU unit
• GIGAChannel connected to the master
• GIGAChannel connected to the slave
• And as many Origin Vaults as you feel you need …….

This would obviously give you an impressive amount of I/O, processing power etc.

Graphics

Graphics cards weren’t an option from SGI , and Origin 200s were never sold as visualisation systems.

However, GIGAChannel neatly adds a load of single-width XIO slots to an O200. This means that single-width XIO graphics boards can be fitted. This does limit you to SI or SE cards from an Octane – however, in theory, you can have a multi-head 4 way machine. Think Octane on serious steroids :-)

Greg Douglas of Reputable did some testing – his post can be found here.

PSITech makes an IRIX supported PCI graphics card – the RAD4C-KM. Speed will be, frankly, laughable compared to the XIO boardsets, but it’s still an option that could be explored.

Owner’s Guide, Datasheets and Whitepapers

The O200 Owner’s Guide can be found on Techpubs.

There are also local copies of:

• Origin 200 Owner’s Guide
• Origin 200 Maintenance Guide
• Origin 200 Datasheet
• High Definition I/O datasheet
• System Overview of the SGI Origin 200/2000 Product Line