Thor Lancelot Simon wrote:

> On Thu, Nov 21, 2002 at 12:28:54AM -0500, vance@neurotica.com wrote:
> > On Wed, 20 Nov 2002, Thor Lancelot Simon wrote:
> > 
> > > > so it looks like it's an R2000 after all.  whaddya know...
> > >
> > > The R2000 and R3000 instruction sets are the same.
> > >
> > > The only difference between the 2100 and 3100 is clock rate.
> > 
> > Is there any difference in implementation?  Or only clock rate?
> 
> The R2000 and R3000 are different implementations of the same instruction
> set; the R3000 achieved higher clock rates.  The follow-on to the R3000
> was the R6000, which implemented an instruction set much more like that
> of modern 32-bit MIPS processors, but which was very expensive, had supply
> problems, and ran quite hot -- unsurprising, since it was implemented in 
> ECL.
> 
> Both the DS2100 and DS3100 use the R2000 CPU.  IIRC, the 2100 runs at
> 14MHz and the 3100 runs at 16MHz.  The DS5000/200 uses the R3000 CPU,
> at 25MHz as I recall.

Look at http://www.netbsd.org/Ports/pmax/models.html.

A quick summary:

	2100:     R2000 @ 12.5MHz
	3100:     R2000 @ 16.67MHz
	5100:     R3000 @ 20MHz
	5000/200: R3000 @ 25MHz
	5500:     R3000 @ 30MHz

The bible (See MIPS Run) says that the R3000 is a "midlife kicker".
Comparing the R2000 to the R3000, it says:

	"It's almost identical from the programmers viewpoint,
	although small hardware enchancements combined to give
	a substantial boost to performace."

Simon.
--
Simon Burge                            <simonb@wasabisystems.com>
NetBSD Support and Service:         http://www.wasabisystems.com/