[rescue] SGI Challenge Memory

[Sheldon T. Hall]

 r.stricklin writes ...
> On Jan 10, 2004, at 5:32 PM, Sheldon T. Hall wrote:
>
> > I have an SGI Challenge L with three MC3 memory boards; the boards are
> > fully populated with 16-MB SIMMs.  That's 32x3=96 SIMMs for a total
> > of 1.5 GB.
> >
> > I have another MC3 board and 12 more SIMMs I'd like to install.
> >
> > At issue is the memory interleaving and SIMM installation, and I'd
> > like some advice.
>
> At issue is the fact that you cannot install four MC3s in a Challenge
> L. You also need the IO4 and an IP19 (or IP21 or IP25) installed, and
> there are only five of these slots in an L.

Well, poop.  An inspection of the owner's manual shows that you are correct.

So ... why all those pages talking about using 4 MC3 boards to get 8-way
interleaving?  Are they actually talking about the Challenge XL?

> > It also seems like having three MC3 boards in the machine might be
> > mucking up the interleaving scheme.
>
> It might be. 'hinv' will tell you what the system is doing with regard
> to interleaving. I would guess it's using two-way interleaving.. or
> possibly a combination of two-way and four-way.

The hinv says ...

Main memory size: 1536 Mbytes, 4-way interleaved

So, I guess I'm OK there.

Fortunately, that nice 100baseT board you brought me recently has the
"other" connectors, so it goes in one of the "other" slots, right?

-Shel