Re: Testing memory in an ULTRA60

["Volker A. Brandt" <vab%bb-c.de@localhost>]

> > Anyway, according to Volker they must be identical because the machine
> > would otherwise reject the bank.
>
> That's not necessarily true.  Most versions of OBP will read the DIMM SPD
> information to come up with a common configuration and use that.  DRAM
> configuration is a complicated mess.  They may even all be the same size,
> but if even one of them has a different layout of banks it can restrict
> the use of the entire bank.  What you really want to do is dump the
> contents of all the SPD data from the DIMMs and compare them, but I don't
> know how to do that offhand without a debug OBP.  You might want to poke
> around in the Forth dictionary to see if there's some way to access that,
> but it's unlikely since it's usually only processed during the config
> phase.

While I'm sure Eduardo is correct, and all that is theoretically
possible, I have never seen anything like it in practice, especially
with those old OBP revs in the U60.  The only really good way would
be to open up the box and look at the part numbers on the memory
DIMMs, though.


Regards -- Volker
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Volker A. Brandt               Consulting and Support for Oracle Solaris
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