[Sunhelp] Sparc 10

[James Lockwood]

On Mon, 15 Nov 1999, Jeff wrote:

> I'm looking into upgrading from my Sparc 2, to an SS10.  The problem is,
> I'm not too familiar with the internals.  If I get a single processor
> Sparc 10, then want to go get another module, do I have to get a special
> dual prcessor one?  And likewise, if I were to go from 2 to 4 (Sparc
> 10's are quad capable right?), do I need a special module with 4 cpus,
> or can I keep each processor?

The SS10 (and SS20 and 4/600) have 2 MBus sockets.  Each socket can hold a
module, each of which can contain 1 or 2 CPU's.

Some CPU's (SM20/30/early SM40) are not MP capable.  Most CPU's come only
one per module (all SM modules except for the SM512).  MP performance with
modules with no e-cache is noticably poorer than performance with modules
with cache due to mbus bandwidth contention.

If your budget is pointing you towards a SS10 or SS20, I'd advise you not
to set your sights on a 4-CPU machine.  The multi-CPU modules are not cost
effective in most cases (and performance drops due to mbus saturation),
you are better off going with a faster uniprocessor machine.  Ultra
1/140's are now quite cheap and will beat any SS10/SS20 except those that
cost far more. 

Try to find either a SS10 with an SM51 module or a SS20 with an SM50 or
above.  These perform well and have good bang for the buck, plus you can
upgrade to 2 CPU's on the cheap.  When you need more performance, sell it
and grab a low-end Ultra.

-James