[rescue] SGI Personal Irises- Free

[Gerhard Lenerz]

On Wed, 23 Apr 2003 22:25:42 +0200
Jochen Kunz <jkunz at unixag-kl.fh-kl.de> wrote:

> On 2003.04.23 20:20 Gerhard Lenerz wrote:
> > On the other hand a 4D/35 (36 MHz R3000) runs circles around
> > an R3000 Indigo -
> Really? What makes it so much faster? Isn't the R3k Indigo IP12 too and
> uses the same RAMs?

I didn't give these two systems too much thought recently, but from what 
I remember IP12 is not equal to IP12. The 4D/35 has the R3000 running at 
36 MHz while on the Indigo it's 33 (or 30) MHz. Maybe more important is 
that as far as I recall "some" busses run faster on the PI and that memory
access is handled slightly different. In regard to the busses I remember 
something about a jumper that has to be set if a 4D/35 is equipped with
Elan graphics (which is a typical Indigo thing) and that reduces the 
clock rate at which the (system?) bus is operating.

This is quite vague, if you're interested I can dive a bit into my 
archives and see if I manage to find anything.


Gerhard