[rescue] sparc10 cpu - what to do.

[Doug McIntyre]

On Fri, Dec 16, 2016 at 09:13:52AM -0500, john wrote:
> I cannot remember the name of the thing, but what was interesting was 
> that a Sparc2 could process the image in about 10% of the time it took 
> on a 486.

Not too surprising. The merits of RISC really shined on many workloads.

> but back to the cpu issue. I have a single SM51. Since these look 
> relatively inexpensive, my thought was to add another one. I'm assuming 
> I need the same part number as it looks like Sun made a number of 
> different SM51's.

The MBUS is fairly robust with that regard. I did run mixed CPUs in a
SS10, an SM41 and SM51. Gained benefits, nothing strange ever happened.
Of course now, you have a lot more choices for very little money that
you would be more properly served by matching the CPUs so the kernel
doesn't get into a strange situtation with mismatching CPU frequency
or stepping. 

> I'm also running two 2Gig drives in this case, one of 
> which is an early one and runs hot.

I think the main reason for old disk failures is the lubrication dries out,
the drive becomes a furnance and starts cooking everything on the
controller board, and either the chips fail, or the disk doesn't spin right.
So yeah, you have age of disk working against you.

If the price of this wasn't so high..
https://www.pc-pitstop.com/scsi_ide_adapters/aec7720u.asp
https://www.pc-pitstop.com/scsi_ide_adapters/aec7730a.asp

A SCSI to SATA bridge and anything sata, even small SSD would just rock on
that system I think. 

> If I add this second CPU, am I likely to need to recompile kernel? Or 
> only if I picked badly when I set it up the first time?

No, multi-CPU support was built into the SunOS 4.1.4 kernel from the start.