9 Oct
2002
9 Oct
'02
12:13 p.m.
From: "Ross Archer"
<dogbert(a)mindless.com>
Jerome H. Fine wrote:
Harsh! :)
Guess it depends on what you mean by "far behind from a
technical point of view."
If you mean that x86 is an ugly legacy architecture, with
not nearly enough registers, an instruction set which
doesn't fit any reasonable pipeline, that's ugly to decode
and not particularly orthogonal, that from purely technical
reasons ought to have died a timely death in 1990,
I'd have to agree.
However, look at the performance. P4 is up near the
top of the tree with the best RISC CPUs, which have
the advantage of clean design and careful evolution.
It surely takes a great deal of inspiration, creativity,
and engineering talent to take something as ill-suited
as the x86 architecture and get this kind of performance
out of it. IMHO.
In other words, making x86 fast must be a lot like
getting Dumbo off the air. That ought to count as
some kind of technical achievement. :)
---snip---
It is all done with smoke and mirrors. We do the same
here at AMD. The trick is to trade immediate execution
for known execution. The x86 code is translated to run
on a normal RISC engine. This means that the same tricks
on a normal RISC engine would most likely only buy about
a couple percent. It would only show up on the initial
load of the local cache. Once that is done, there is
really little difference.
Choices of pipeline depth, out of order execution, multiple
execution engines and such are just the fine tuning.
Intel, like us is just closer to the fine edge of what
the silicon process can do than anything tricky that
people like MIPS don't know about.
On a separate subject, I was very disappointed in the
Intel Museum. I'd thought it might be a good place to
research early software or early IC's. They have vary
little to offer to someone looking into this level of
stuff. Any local library has better references on this
kind of stuff ( and that isn't saying much ).
Dwight
Jim
Kearney wrote:
I just had an email exchange with someone at
Intel's Museum
(http://www.intel.com/intel/intelis/museum/index.htm)
Jerome Fine replies:
I am not sure why the information is so blatant in its
stupid attempt to ignore anything but Intel hardware
as far a anything that even look like a CPU chip, but
I guess it is an "Intel" museum.
Of course, even now, Intel, in my opinion, is so far
behind from a technical point of view that is is a sad
comment just to read about the products that were
way behind, and still are, the excellence of other
products. No question that if the Pentium 4 had been
produced 10 years ago, it would have been a major
accomplishment.