Summary: Solbourne vs MP

From: Wolfgang Henke (
Date: Sat Apr 11 1992 - 23:56:17 CDT

The quick answer is that it depends on your application. CPU intensive
is better on the MP, while I/O limited systems should consider the
Solbourne. Since we have an I/O problem here, you will see me posting
from a Solbourne shortly.

From: (Rand S. Huntzinger)

   The advantage I'm talking about is primarily due to the software. The
current Sun system is a bit of a fast job because Sun was concentrating their
efforts on Solaris 2.0. Basically, they're limiting one CPU to the kernel.
This isn't quite the same as master/slave but pretty close. The Solbourne
can have multiple processors in the kernel and the locks occur much closer
to where they are actually needed. When you're I/O bound this is apparently
a major bottleneck in the current Sun OS. This is supposed to be fixed in
the newer release.

   As far as the hardware is concerned, I doubt that there will be much of a
difference. Yes, the Sun has to go from Mbus to Sbus or VME and then do the
I/O. But then the Solbourne is going to go from Kbus to VME and then do the
I/O. Solbourne has, I believe, some Kbus to VME adaptor cards which give you
a performance advantage over their VME bus (by adding another 1 slot VME), but
these take precious Kbus slots and if you end up with a Solbourne like ours
you may wish you have more than you do. [With the I/O card, CPU's and memory
our Kbus is full. There are other models with more Kbus slots than we have
(7) where you may be able to sacrifice a CPU or memory card for an additional
fast I/O channel.

   What I'm saying is largely conjecture. We have a Solbourne and we have
Sun 630's and 490's. They perform about the same for our purposes, but we
tend to be CPU bound, not I/O bound. We can't get enough CPU's around here
to keep everybody happy. People with lots of users and which are heavily I/O
bound have reported on the net that having more CPU's with the current Sun
system (4.1.2) was more a liability than a help. So in today's configurations,
Solbourne has a big advantage for what you would describe as your needs. Once
Sun has their SVR4 system up and tuned up, I would expect that the two would
be pretty comparable in performance - but I really don't have hard evidence
to back it up. In our environment, the machines are pretty much comparable.
In a couple of years, both companies will probably have machines much more
suitable for what you want - but who can wait?

From: (Jim Prescott)
You can get info direct from Solbourne at (800)356-8765. They have
processors as fast as Sun's. Their big machines can hold at least 8
CPU's. You can add tons of fast memory (Sun has much slower access to
memory beyond 128M). They have full symmetric multi-processing so their
performance scales much better than Sun's asymmetric implementation.
Solbourne claims to design things more like mainframes than workstations
(more attention to I/O throughput, interactive performance, reliability
and expandability).
Solbourne considers themselves to be a SPARC compatible, not a Sun
clone. Their systems provide things that Sun doesn't. With application
code they guarantee 100% compatibility. Device drivers tend not to
When we priced things they were also far more expensive. We bought a
670MP-2 (actually we bought a 3/160S-4, upgraded it into a 670MP-2 and
saved $10k; Sun's pricing is pretty bizarre).

Wolfgang Henke 

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