SGI Model Numbers
The specifications of Silicon Graphics machines are difficult to determine without the machine being operational. On newer machines, the model number can be used to figure out what processor originally shipped with the machine (older machines, especially the larger models, have only a chassis model number visible).
General rules for reading model numbers
Decoding SGI Part Numbers
CMN B xxx yy zzz
Personal IRIS model numbers
Personal IRISes predate the convention of having processor codes in the model number. CMN-B001 is the model for the Personal IRIS 4D/20 or 4D/25. The back label has a "Configuration" field which indicates the processor and graphics options originally installed (E.g. "Configuration: 4D/25 Super Turbo")
Indigo model numbers
The Indigo model number is CMNB003. This indicates a 33MHz R3000 machine. The R4000 Indigo model number is CMNB003B. The model number does not indicate the speed of the processor in R4000 machines.
Indigo2 model numbers
The base model for the Indigo2 machine (as shown on the sticker) is CMNB007 The rest of the model number indicates the processor type and speed originally shipped. If a machine was upgraded/downgraded by Silicon Graphics, a new model number sticker will be put on indicating the new model. Keep in mind that many hobbyist machines are upgraded or put together from parts so the model number may not be accurate
R4000/R4400 based machines:
The model number on the back will be followed by a Y and a number. The number is the external oscillator speed (1/2 of the processor speed). For instance, a CMNB007Y100 is a 200MHz R4400 It is not known if there is a distinction between models with different cache types (e.g. the 200MHz R4400, which comes in both 1MB and 2MB secondary cache models). It is suspected that this model number is also applicable to the rare R4600 models (the number would be CMNB007Y66)
R8000 based machines:
The R8000 will have the model number CMNB007YT75, since only 75MHz R8000 processor modules were shipped for the POWER Indigo2 IP26.
R10000 based machines:
The Indigo2 IMPACT R10000 will have a CMNB007AF model number. The last digits indicate the processor clock (either 175 or 195). A CMNB007AF195 is a 195MHz R10000 Indigo2.
Indy model numbers
The Indy base model number is CMNB006. R4k (R4000, R4400, R4600) models follow the Indigo2 convention of using a Y plus the external oscillator speed (1/2 of the processor speed). CMNB006Y66 would be a 133MHz R4600 based machine. R5000 models use a T followed by the speed of the processor. CMNB006T150 would be a 150MHz R5000 Indy.
Octane model numbers
The Octane model number is CMNB015 Octanes shipped with several generations of processors, and like Indigo2s the letters determine the processor type and the numbers at the end the frequency.
R10000 based single-processor Octanes:
The R10000 based Octane will have the letter designation ANF followed by the processor speed. A 250MHz model would be CMNB015ANF250
R12000 based single-processor Octanes:
The R12000 based Octanes have ANG as the middle letters, again followed by the processor speed. A 300MHz model would be CMNB015ANG300.