On Wed, May 03, 2006 at 01:02:58PM +0200, Christer O. Andersson wrote:
> On Wed, May 03, 2006 at 06:35:12AM +0200, Magnus Svantesson wrote:
> > I have for quite some time now been trying to revive a  3X 90 MHz
> > Hypersparc-equipped Sparc 20.
> > CG6, 512 Mb and a whooping external 36 GB HD.
> 
> 
> The default kernel probably only supports one processor. You can
> change that kernel to a mp kernel later. 3 processors seems a bit
> odd?
> 

One of the fun things about Sparc 20s and Hypersparcs is that one can 
pretty much mix and match them.  You have 2 MBUS slots and hypersparcs came
in single and dual cpus per board.  I've run a 180 with a dual 55, a pair of
180s, a dual 90 and a dual 100, a 180 with a dual 100 etc etc.  It seems that if
you can get to an openboot prompt you'll be able to boot netbsd and netbsd will
basically be sensible.  It's quite nice.

The only two things I've noticed are that:

- CPU0, the one in the lower slot, runs the interrupts.  This means for
high interrupt situations (ie I/O) you want this to be the fastest cpu.

- Long running jobs, especially ones which only use one cpu, tend to
run most often on the slower CPUs.

Finally in recent versions of current top tends not to update CPU bound
jobs that don't migrate around to different processors.   Other than that
it's great fun, even if it's "unsupported" by sun.

cheers

bruce

-- 
edoneel@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org