[SunRescue] SS4/SS5/SS10 funzies.....(:+}}...

[Joshua D. Boyd]

Hmm, I was going to say I know of a machine around here with an 80mhz
supersparc, but I ran dmesg on it an found that it wasn't what I was told
it was.  It is a dual supersparc 40 machine, not a dual 80 like I was
told.  That explains a few things.  Suprising how a dual 40 doesn't feel
much worse than a 170mhz sparc 5.

--
Joshua Boyd

On Tue, 3 Apr 2001, James Lockwood wrote:

> On Tue, 3 Apr 2001, Joshua D. Boyd wrote:
> 
> > So, how does a 80mhz SuperSparc supposedly compare to the 170mhz chips in
> > SS5s?  If any machine were possible, what is that fastest non-ultra CPU
> > sparc available?  Is there anything as dramatic as the difference between
> > the 150mhz R4400 vs the 75mhz R8000?
> 
> Sun didn't ship production 80MHz SuperSparcs.  The SM81 (85MHz) probably
> holds fairly even with the 170MHz TurboSparc, with a boost to code that
> fits the Supers cache better (1MB vs 512KB).  The microSparc-II based
> sun4m's have lower memory latency across the board so truly cache-busting
> code on a SS5/110 may actually beat out everything else.
> 
> For "typical" apps, a SS20 with HyperSparcs will be hard to beat.  A
> 150+MHz Hyper will outperform the Supers for most code and a 200 should
> for everything except very rapid context switching (virtual vs physical
> cache mapping bites the Hyper here, it will have to do more cache flushes
> on average).
> 
> The R8k is a funky chip.  It's great at certain benchmarks and a very
> narrow (FP intensive) opcode mix.  Stay within that and you get terrific
> performance, stray outside and it goes into the toilet.  Faster R8k's
> (such as used in the Power Challenge series) were better balanced but the
> R8k/75's used in the Indigo2's do not offer a huge performance boost over
> the R4400's.  I'd rather have a 200+MHz R4400 than the R8k/75.
> 
> Of course, if you wanted a "stealth" Ultra, you could always get a
> SparcEngine Ultra 20 and put it into a SS20 case.  Rare boards though.  :)
> 
> -James
> 
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