13 Nov
2003
13 Nov
'03
7:50 p.m.
On Nov 13, 21:48, Eric Smith wrote:
I thought the R4600 was, though maybe it was early 1994, but actually I
wasn't claiming any particular date -- just that they do speculative
execution.
until
Peter Turnbull wrote:
> Then I get three because I understood it, and can think of
processors
that do it --
and a few more because I've not only got some (MIPS
R4600, R5K and R10K)
None of which were available in November 1993. And having used the
R4600 quite a bit in 1996, I'm fairly sure that it did *not* have
speculative execution. The Pentium
can do speculative execution as well,
The Pentium was superscalar, but did not do speculative execution.
SE was introduced with the Pentium Pro, which was not introduced 1995.
I meant the Pentium family. Yes, I knew the Pentium Pro was the first
-- and it didn't work all that well so Intel changed the branch
prediction algorithm for the Pentium II.
--
Pete Peter Turnbull
Network Manager
University of York
14 Nov
14 Nov
12:35 a.m.
I thought the R4600 was, though maybe it was early
1994, but actually I
wasn't claiming any particular date
There's no challenge in naming a few parts that have speculative
execution. In my original posting, I specifically stated that I
couldn't think of any processors introduced before Nov. 1993 that
had speculative execution, other than the IBM 7030 (Stretch, 1961).
I wasn't claiming that there weren't any others, just that I didn't
know of any. I was *almost* willing to claim that there weren't any
microprocessors with speculative execution until after Nov. 1993.
However, I may have been a bit hasty. Although I don't think the
R4600 was out at that time, after thinking about it some more it
occurs to me that some earlier R4K series parts may have had
speculative execution, and probably the DEC Alpha (20164). So if
I were the arbiter for geek points, I guess I'd have to give you at
least partial credit. :-)
I meant the Pentium family.
Is there really a Pentium family? Aside from the Pentium Pro,
Pentium II, and Pentium 3, which use similar cores, there seems to be
little microarchitectural similarity between parts for which Intel uses
the "Pentium" name. For instance, there seems to be more similarity
between the i486 and Pentium cores than between the Pentium III and
Pentium IV cores, despite the fact that the Pentium was superscalar
and the i486 was not.
2:33 a.m.
New subject: more talking to the press - Microprocessors, Speculative execution, etc.
According to a chart in Microprocessor Report identifying the attributes of
all the major superscaler microprocessor chips available as of October, 1992,
only the Motorola 88110 had speculative execution.
Back in the sixties, I was working at IBM's Development Lab in Poughkeepsie,
NY when we (IBM) announced the IBM 360/91 - which one could argue was the
first computer that explored superscaler techniques (Of course, it was
definitely NOT a microprocessor ;-)
Of course, some CDC folks might argue with me on who was first :-)
BTW: I used the "Nancy" simulator (simulating 360 architecture) on the IBM
Stretch to develop an early diagnostic OS for the 360 - and for sure the
early 360's could not be considered superscaler - although I would argue that
Stretch itself was "close"...
Cheers,
Lyle
On Friday 14 November 2003 05:35, Eric Smith wrote:
--
Lyle Bickley
Bickley Consulting West Inc.
Mountain View, CA 94040
"Black holes are where God is dividing by zero"
I thought the
R4600 was, though maybe it was early 1994, but actually I
wasn't claiming any particular date
There's no challenge in naming a few parts that have speculative
execution. In my original posting, I specifically stated that I
couldn't think of any processors introduced before Nov. 1993 that
had speculative execution, other than the IBM 7030 (Stretch, 1961).
I wasn't claiming that there weren't any others, just that I didn't
know of any. I was *almost* willing to claim that there weren't any
microprocessors with speculative execution until after Nov. 1993.
However, I may have been a bit hasty. Although I don't think the
R4600 was out at that time, after thinking about it some more it
occurs to me that some earlier R4K series parts may have had
speculative execution, and probably the DEC Alpha (20164). So if
I were the arbiter for geek points, I guess I'd have to give you at
least partial credit. :-)
I meant the Pentium family.
Is there really a Pentium family? Aside from the Pentium Pro,
Pentium II, and Pentium 3, which use similar cores, there seems to be
little microarchitectural similarity between parts for which Intel uses
the "Pentium" name. For instance, there seems to be more similarity
between the i486 and Pentium cores than between the Pentium III and
Pentium IV cores, despite the fact that the Pentium was superscalar
and the i486 was not.
8199
days inactive
8199
days old
2 comments
3 participants
participants (3)
-
eric＠brouhaha.com -
lbickley＠bickleywest.com -
pete＠dunnington.u-net.com