seeking SS20 - test-drb@ccmp.vtda.org

14 Nov 2008

Yes, I have one with a pair of SM52Xs somewhere, for quad SuperSparc
 at 50 MHz with 1 MB cache each.  A couple of years ago I put NetBSD 2.0
 on it.  Compiling Apache, it was just a little bit faster than dual
 SM71.  Of course, SMP was brand new in NetBSD 2.0

The bummer is that with the 50 MHz CPUs, you have to run 40 MHz bus,
since the bus must always be lower frequency than the CPU.  
What I always wondered is, if Sun could run the SM41 at 40.3 MHz and
 use the 40 MHz bus, why did the SM51 not run at 50.5 and allow 50 MHz
 bus?  I assume the obvious reason was "they tried and it didn't work."

John

der Mouse wrote:
...
 > I think the 20 can actually do quad-CPU; while it
has only two Mbus
> slots, I seem to recall that someone made Mbus modules with two CPUs in
> a single Mbus form factor.  
Curt wrote:
...
 It can do quad... Sun had the SM52X (2 SM51s on a
almost
double wide cpu card... you could the put two of them in.
Downside was you lost 2 sbus slots.  The Sun sold Hypersparc
module HS12 was a dual 100mhz cpu (I believe it was normal
width... so you didn't lose sbus slots to go quad). 
...
 If you went with Ross Hypersparc modules there were
various
dual cpu on one module configurations....  I know there was
2 variants of dual 125mhz modules (256K, 512K, or 1M of cache).
I know there was a dual 142mhz 1M cache module (which I
believe was extra wide).  Those are ones I have or have had.
There are many more. 