Until the introduction of the Octane, the Indigo 2 was SGI’s top end workstation. However, performance is still excellent and it still makes a very fast and useable workstation. Recently, prices have been plummeting, and an R10000 MaxImpact Indigo 2 represents superb value for money.

There are two different variants of the Indigo 2 – one with a green (called teal) case, and one with a purple case. RAM, CPU types, and graphics options available vary between the two.

There are other CPU options, mostly the older R4000 and R4600 processors, which have the same specification as those available to the Indy. More can be found here.

You can upgrade an R4400 Indigo 2 to an R10000 processor. You will need a new motherboard, new powersupply, new processor module (duh! :-) and you may also need to replace the expansion backplane. However, it would probably work out cheaper to just sell your old machine and buy a newer one.

RAM:

R4400 based Indigo 2 machines have 12 SIMM slots, giving 3 banks of 4 slots. They can take 4mb, 8mb, 16mb or 32mb 72pin parity SIMMs, giving a total of 384mb.

R10000 based Indigo 2 machines also have 12 SIMM slots, with 3 banks of 4 slots. They can take all the above SIMM sizes (again, 72pin parity) but can also take 64mb SIMMs, giving a total of 768mb RAM.

It appears it is possible to squeeze in 1GB RAM into late model R10k machines – Ian’s site has the info here.

Graphics options:

This is the tricky one :-) The Indigo 2 has a wealth of different graphics options, and two different expansion backplanes that support different options.

The earlier, green (called Teal) cased Indigo 2 has the following options:

• 24bit XL – no hardware acceleration, basically a 2D card

• 24bit XZ – 2 geometry engines, hardware Z buffers

• 24bit EX (Extreme Graphics) – 8 geometry engines, hardware Z buffers

Later Teal Indigo 2s had an upgraded XZ card with 4 GEs, although I’ve never seen one.

The later, purple cased Indigo 2 has the following options:

• Solid Impact – 1 GE(1), 1 RE(2), no hardware texture mapping

• High Impact – 1 GE, 1 RE, hardware texture mapping, 1MB or 4MB TRAM(3)

• High Impact (High-AA)(4) – 2 GEs, 1 RE, hardware texture mapping, 1MB or 4MB TRAM

• Max Impact – 2 GEs, 2 REs, hardware texture mapping, 1MB or 4MB TRAM

(1) GE – Geometry Engine
(2) RE – Raster Engine
(3) TRAM – Texture RAM
(4) The High-AA board is a bit rare, and I haven’t seen it mentioned anywhere in SGI literature, but it’s basically a High Impact that carries out some operations at Max Impact speeds (most notably Anti-Aliasing, hence the AA)

Note that it’s possible to mix and match graphics boards to create a dual-head workstation. A Max-Impact/Solic Impact R10k is a truly splendid workstation :-)

If you want to upgrade a teal Indigo 2 to IMPACT graphics, you not only need to get the required board sets, but you will also need to replace the expansion backplane, and probably the power supply as well.

Ports:

• External fast SCSI (2nd channel)

• 2 Mac-compatible serial ports (RS422)

• PS/2 keyboard and mouse

• 10-BaseT or AUI ethernet

• Audio I/O (microphone, headphone, line-in, etc.)

• Bi-directional parallel port

• 3 EISA slots, and 2 GIO-64 slots

Drives:

The Indigo 2 has a decent amount of space inside for various drive configurations. There is space for 2 3.5″ hard drives, an externally accessible 5.25″ slot for a CD drive, and an externally accessible 3.5″ full height slot, for either a Floptical drive, or a DAT drive.
The internal devices are connected to one SCSI channel, and the external devices are connected to another, so you can spread devices across 2 seperate channels to improve I/O performance if needed.

All 3.5" and 5.25" devices are mounting on custom SGI sleds. These sleds present a 50pin SCSI cable to the device, and have a custom 80pin connecter which plugs into the Indigo2 chassis – it looks like SCA.

The internal SCSI bus is SCSI-2 10mb/s. Any non-HVD drive will work in an Indigo2. If the drive doesn’t have a 50pin connector, who will need to buy and fit a converter. However, note that the combined depth of a hard drive + converter may be too much to fit on the sleds.

More information:

• Greg Douglas of Reputable has archived some excellent posts explaining the various graphics options.

  A detailed overview of green (Teal) Indigo 2 graphics options can be found here:
  http://www.reputable.com/indigogfx.txt

  A detailed overview of the various IMPACT graphics sets is here:
  http://www.reputable.com/impact.txt

• Ian Mapleson has an excellent set of links for all sorts of information about the Indigo 2. It can be found at:
  http://www.futuretech.blinkenlights.nl/indigo2/

Owner’s Guides and Datasheets

The Owner’s Guide for the Indigo2 can be found on Techpubs, as can the Owner’s Guide for the Indigo2 Impact.

A local copy for the Indigo2 can be found here , as well as for the Indigo2 Impact.

A local copy of the Indigo2 Impact datasheet can be found here.

The Challenge S is SGI’s entry level server. It is essentially an Indy, with some key parts removed, and some added.

The Challenge S is designed to run as a headless server – as such, it has no ports for a keyboard, mouse, or video out. It also lacks the S-Video in and IndyCam in ports that the Indy has, and also has no sound.

The other main difference is that the primary ethernet port on the Challenge S is AUI – on the Indy it is 10-BaseT. This means that you’ll need to get an AUI transciever if you want to connect to a 10-BaseT or 10-Base2 network on the primary port. However, the Challenge S does come as standard with the Mezzanine SCSI board.

This is a single height GIO board, with 2 fast-wide-differential SCSI ports (providing 2 seperate channels) and a 10-BaseT ethernet port.

Serial port A is where you should plug in a serial terminal to administer the machine. This is deemed the ‘console’ port. I’ve used everything from wretched old VT100 terms, through console networks, to a Palm Pilot.

As it’s based on the Indy, upgrades are very easy. The Challenge S will take the same memory, hard drives, and CPU modules as an Indy. As it shares the same PROM, it could even be configure to have the console as a graphics card. There is room to fit one, even with the Mezzanine card fitted.

More information can be found on the Indy model summary page.

Summary:

• Max. 256mb RAM, as in the Indy

• No keyboard or mouse port

• No graphics card, so no monitor

• No Video input, and no sound

• Mezzanine SCSI board, with twin SCSI channels and 1 10-BaseT port

• Otherwise a standard Indy

Owner’s Guides

The Challenge S Owner’s Guide can be found on Techpubs.

A local copy can be found here.

PC on a CPU module means Primary Cache (ie. only on-die cache). SC means Secondary Cache (ie. L2 cache on the module).

RAM:

The Indy has 8 slots, taking 72pin parity RAM. 4 SIMMS per bank, 2 banks total, giving a maximum of 265mb.
Memory can be either 4mb, 8mb, 16mb or 32mb, and must be the same size and speed within a bank.

Graphics:

Indy’s come with 3 main graphics options – 8bit XL, 24bit XL, and the XZ. The XL cards have decent 2D performance, but everything else is offloaded to the CPU. The XZ has some 3D acceleration (hardware Z buffer, geometry/lighting acceleration). However, it seems to be slower than the XL cards for 2D work.

Ports:

Lots of connectivity comes with the Indy as standard:

• ISDN BRI port

• PS/2 keyboard and mouse

• 10-BaseT or AUI ethernet

• External fast SCSI

• S-Video in

• Digital video in

• IndyCAM

• Sound (headphones, microphone, line-in, etc.)

• Bi-directional printer port

• 2 Mac-compatible serial ports

Drives:

The Indy has 2 internal 3.5 inch drive bays. These can either take the Floptical drive (SCSI drive that reads/writes normal floppies, and special 21mb ‘floptical’ disks) or normal hard drives.
If you want a CD or DAT drive, these can be connected via the external SCSI port – it is one SCSI channel though (unlike some other machines).

The internal SCSI connecters are 5mb/s SCSI-1. The cables for the hard drives are standard 50pin SCSI connectors. As SCSI as backwards compatible, any non-HVD drive will work. If the drive doesn’t have a 50pin connector, you will need to buy and install a converter.

Several people have reported success using IDE->SCSI converters, and installing IDE drives in their Indys.

More information:

• Greg Douglas has an excellent technical overview of the Indy at:
  http://www.reputable.com/indytech.html

• Ian Mapleson’s 2nd Hand Purchasing advice is a must-read if you’re thinking of getting an Indy. It can be found at:
  http://www.futuretech.blinkenlights.nl/indyinfo.html

Owner’s Guide

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

A local copy can be downloaded from here.

The Octane was SGIs top-end workstation. It uses a similar architecture to the larger machines like Origin 2000 and Onyx 2 – multi-processor with a large bandwidth crossbar.

The Octane comes with a range of processor options, and is capable to taking 1 or 2 processors. The processors are held on daughter boards which attach to the Octanes motherboard. As such, you can’t buy a second CPU and plug it in – you need to ditch your existing CPU and replace it with a dual-CPU board. This accounts for the relative high price of dual CPU boards as opposed to single CPU boards on the second hand market.

There are two series of Octanes. Early machines used IMPACT graphics and are limited in the level of processor upgrades. Later models have VPRO graphics and their processor options are still being added to by SGI.

Even thought IMPACT graphics can be considered old in computing terms, you can’t make straight comparisons between (say) an R10k-195 Solid IMPACT Indigo 2 and an R10k-195 Octane SI. The enormous amount of I/O bandwidth available across Octanes crossbar, plus some neat tweaks in the implementation of IMPACT, mean that the Octane has significantly faster graphics. See Ian Mapleson’s performance stats for more in-depth comparison – in particular, his comparison of Indigo2 and Octane.

The IMPACT-based graphics options for Octane are as follows:

• SI –
  

• SE –
  

• SSI –
  

• SSE –
  

• MXI –
  

All the ‘S’ cards (with no hardware texture support) can have TRAM boards added for instant hardware texture support. SI and SE can take one TRAM, SSI and SSE can take two. SSI and SSE with 2 TRAMS are equivalent to MXI.

Physically, the Octane is pretty large – almost square. Looking from the back, we have the motherboard on the left (mounted sideways – CPUs and DIMMs facing in towards the middle of the chassis.
In the middle-bottom of the chassis is the power supply – above that, the PCI card cage. Above that, at the middle-top of the chassis, are the drive bays – 3 3.5″ bays. Sorry, no internal CD-ROMs in Octane :-( But room for a couple of high speed SCA drives and a DAT drive.
The right hand side of the chassis is taken up by the 4 XIO slots. Throwing in multiple graphics cards will give you a dual-head machine. As long as you can get the cooling right, it should be possible to make a triple or quad head machine.

Storage

Octanes have 3 internal 3.5" drive bays. These provide SCA connectors and are a 40mb/s SCSI-2 bus. Drives need to be mounted on custom SGI sleds – these are the same as used in Origin 200s and 2000s.

Due to the depth of the sled and the space for the drive, you are unlikely to fit a hard drive + SCSI converter. Because of this you’ll only really be able to fit SCA drives internally in on Octane. However, as SCSI is backwards compatible, you can fit the latest 15k RPM LVD drives.

Owner’s Guide, Datasheets and Whitepapers

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

There are also local copies of:

• Octane Owner’s Guide
• Octane Datasheet
• Octane Digital Video Datasheet
• Octane Personal Video Datasheet
• Octane Networking Datasheet
• Octane CAD Duo Datasheet
• An Illustration of the MIPS® R12000TM Microprocessor and OCTANE System Architecture
• Introducing the Architectures for the Next Generation
• Entertainment Solutions White Paper

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