PDP11/55 sells on Ebay for 5K$ - was it really the fastest 11?

[Lyle Bickley]

On Sunday 17 April 2005 22:00, you wrote:
> snipe
>
> Lyle wrote:
> > >  I expected  an 11/70 to be instruction for instruction faster - but
> > > add all the cache and complexity - maybe the 55 with bipolar ~was~
>
> faster?
>
> > > How about compared to a 11/70 with a PEP70 instead of factory memory
> > > and cache?
> > > Isn't a 55 just a 45 with bipolar instead of core? or was that a 50?
> >
> > Read "Computer Engineering" (Gorden Bell, J. Craig Mudge, John E.
>
> McNamara),
>
> > Copyright 1978 by Digital Equipment Corporation
> > Page 408
> > --------
> > Model   Basic Instructions Floating Point
> >         Inst. per second*   Inst. per second
> > -------------------------------------------
> > 11/70   36                 671
> > 11/55   41                 725
> > * Relative to 11/03
> > No brainer - the 11/55 wins hands down.
>
> sigh - I haven't memorized the DEC sacred texts yet;) no hardcopy, only
> pdf...
--snip--
> Running code withing the cache should have beaten the 55!

I'll stick with Gorden Bell.... :-)

Lyle

-- 
Lyle Bickley
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"