hmmmm i just ran clockometer from the newer technology gauge series...my
Q650 reads out as a 68040 running at 33.33mHz. wierd eh?

-xiamin
Technomagus artium occultarum detestibiliumque Nargumm Industries
http://www.cris.com/~ingerrn
http://www.netvirtual.com/iris/simon/art.html

On Mon, 21 Oct 1996 kenn@eden.rutgers.edu wrote:

> >> According to Apple the Q650 uses a 68040/66 and the C650 uses a 68040/50, 
> >> at least that's what they posted in their Apple Spec Data Base on their 
> >> Web page back in May. No Centris or Quadra is listed that runs at either 
> >> 25 or 33 Mhz. They're all either 40, 50, 66 or 80Mhz.
> >
> >Actually, the number for processor speed that you normally see posted 
> >(and the number that I've apparently been using so far in my 
> >machine-status document) is the data bus speed, not actually the CPU 
> >speed.  However, since I think that the bus is the limiting factor, we 
> >might as well leave it that way, unless someone has a convincing argument 
> >for going the other way ;-)
> 
> Referring MC68040 running at 25/33/40MHz as 68040/50, /66, /80
> respectively, is a marketing ploy solely devised by Apple.  I've never seen
> a single publication made by Motorola which refers to these chips as
> running at 50, 66, or 80MHz.  
> 
> 68040s have been, using Intel's term, partially "clock-doubled" from its
> birth, unlike 486s which later made "clock-doubled".  And I think Apple
> tried to make their products *look* faster by referring PCLK frequency
> (which is double BCLK frequency) instead of the official "Frequency of
> Operation" defined in the manual (which equals to BCLK).  For example, the
> raw processor speed of the MC68040/33MHz (referred by Apple as "68040/66")
> is considerably lower than that of the "clock-doubled" 486DX2/66MHz, though
> I don't remember the exact figures.
> 
> Anyway, that's the whole story as far as I know.
> 
> ken
> 
>