On Sat, 11 Sep 1999, J.S. Havard wrote:
>You know, if there is one good the about Pee Cees, it is that whatever can
>run on a 12MHz 386 can run on a PIII Xeon 500MHz box.  It may not be
>optimized (at that speed, who could tell?), but atleast it will work!  As
>great as the vax is, this is something that could have been better.  Low
>level stuff.  There is so much work that must be put into getting it to
>run on the next model, it just isn't even funny.

  Umm...that's because there's actually some *advancement* in the VAX family. 
Intel's processor design isn't all that different from the '386 to the PIII,
with the possible exception of the '586->PPro step.  And for all their marketing
that says the PPro->PII or the PII->PIII were such revolutionary steps...bull. 
Look at the design.  It's the same damn processor...the PPro went to the PII
because they couldn't get their fab yields up with big on-chip caches, and from
there on up to the PIII it's primarily a matter of increasing clock rates on
the same tired design.  We're talking about the folks who integrated their FPU,
added two simple instructions, and called it a "new processor" (386->486) and
then, off the hook, rested on their marketing department for a couple of
years...Sure, later they did a few really cool risc and post-risc things in the
PPro (out-of-order execution in the core, instruction decomposition into u-ops,
etc) but can that really hold up nearly fifteen years of processor evolution?

  Sure the VAX-11/780 executes pretty much the same instruction set as my zippy
little VAX-4000/400...but compare the designs of the two processors.  Look at
all the architectural variations...different I/O buses, different memory buses,
different kinds of caches...sure, maybe they could have done better with
compatibility, but at what expense?

  [Not flaming you John, you make an excellent point, just a little friendly
debate...I got out of bed in a weird mood today :-)]

                     -Dave McGuire