[rescue] SGI

[John-Paul Stewart]

On 2023-10-03 00:35, Thomas Pelki via rescue wrote:
> 
> I am still trying to decide what CPU mine has in it.

You can often tell by looking at the "Model No" label on the back.
Indigo2 is CMNB007.  If that's all it says, then it is most likely an
early 100MHz R4000 CPU.

Most model numbers append Yxxx where 'Y' is a literal letter Y
representing R4000, R4400, and R4600 CPUs and 'xxx' is two or three
digits which indicate the bus speed -- half the CPU's clock rate.  For
example, Y125 for the 250MHz R4400 or Y66 for the 133MHz R4600.

If the model number ends if 'AFxxx' then you've got an R10000 CPU and
'xxx' is the actual CPU speed, either 175MHz or 195MHz.  But that's
unlikely in a teal case; by the time of the R10K CPU they were in purple
cases.

Very rare is the YT75 model number which indicates the R8000 CPU at
75MHz.  Just don't confuse YT75 with plain Y75!  If you have one of
those, consider yourself very lucky.  (And consider me very jealous!)

Of course, it is always possible that the CPU has been changed and
doesn't match the label, but it's a good starting point to figuring out
what you've likely got.

There's lots of info to help you figure it out at:
http://www.sgistuff.net/hardware/systems/indigo2.html