[comp.sys.ibm.pc.hardware] Cyrix CX-803D87-20 Coprocessor

reisert@ricks.enet.dec.com (Jim Reisert) (08/05/90)

Hi,

I heard good things about these chips on the net, so I bought one today.
Are there any tests that I can run that will validate that it's just as good
as an Intel 80387 (it passes the included diagnostics), or I guess someone's
word who has run such tests would be sufficient.

thanks...jim

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 Equipment Corporation."

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nmouawad@water.waterloo.edu (Naji Mouawad) (08/05/90)

In article <14244@shlump.nac.dec.com> reisert@ricks.enet.dec.com
(Jim Reisert) writes:

>Hi,
>
>I heard good things about these chips on the net, so I bought one today.
>Are there any tests that I can run that will validate that it's just as good
>as an Intel 80387 (it passes the included diagnostics), or I guess someone's
>word who has run such tests would be sufficient.
>

Huh ? Sorry, I may look like a fool, but a Cyrix ? Gee I'm really
out of touch ... The only non-intel co-processor I've heard of is the Weitek
It seems that this beast is faster amd much more expensive than the Intel
kitter...

Now, would any of you net-lander comment on this ... how many co-processor
are there ? Tested,, untested, price, compatibility etc ...

e-mail or post.

>thanks...jim

Thanks. 
Naji.

P.S. I've posted some times ago a message about MNP level five modems
I recieved several repsonds that clearly showed me I don't have any
clue as to what I was talking about. As soon as I resolve my current
problem, I'll post a summary. Thanks for those of you who sent me
e-mail.
-- 
         ---------------+-------------------------------------------
        | Naji Mouawad  |       nmouawad@water.uwaterloo.edu        |
        |  University   |-------------------------------------------|
        | Of Waterloo   | "Thanks God, we cannot prove He Exists."  |

scjones@thor.UUCP (Larry Jones) (08/05/90)

In article <1990Aug4.220844.7349@water.waterloo.edu>, nmouawad@water.waterloo.edu (Naji Mouawad) writes:
> Huh ? Sorry, I may look like a fool, but a Cyrix ? Gee I'm really
> out of touch ... The only non-intel co-processor I've heard of is the Weitek
> It seems that this beast is faster amd much more expensive than the Intel
> kitter...

There are now three sources of plug-compatible coprocessors.  (The
Weitek is faster and more expensive, but it's not plug-compatible --
you need a special socket [or adapter board] and special software to
use it.  Standard 80287/80387 code can't use it.)

Advanced Micro Devices (AMD) is now selling their copy of the
80287-10 for MUCH less than Intel does.  This chip is as exact
copy of Intel's (they have an agreement under which AMD got
all the info).

Cyrix makes clones of both the 80287 and 80387.  These are slightly
faster than Intel's parts and a little bit cheaper.

IIT also makes clones of bothe the 80287 and 80387.  These are a
good bit faster than Intel's parts for about the same price.
----
Larry Jones                         UUCP: uunet!sdrc!thor!scjones
SDRC                                      scjones@thor.UUCP
2000 Eastman Dr.                    BIX:  ltl
Milford, OH  45150-2789             AT&T: (513) 576-2070
You should see me when I lose in real life! -- Calvin

ndoduc@framentec.fr (Nhuan Doduc) (08/07/90)

In <128@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes:

>There are now three sources of plug-compatible coprocessors....
               ----> 3 and a half: the 287XL is also a good value
                     287XL ~= IIT 2C87 on most FP intensive benchmarks

>Cyrix makes clones of both the 80287 and 80387.  These are slightly
                    ------> NOT of 80287 (387sx yes, but no 287)
>faster than Intel's parts and a little bit cheaper.
----> in many tests done here, Cyrix is MUCH FASTER than i387 (except at 33Mhz)

>IIT also makes clones of bothe the 80287 and 80387.  These are a
>good bit faster than Intel's parts for about the same price.
----> I hate comparing IIT and Cyrix here but can send the above-mentioned
benchmark report to anyone who request it.

>SDRC  
----> is SDRC the one who provides DIAG.EXE (an excellent test BTW)with one of
the above clone ?

----> BTW, when will IIT or Cyrix or XXX make 6888x clone ?

--nh
N.DoDuc, 
Framentec-Cognitech, Paris, France, ndoduc@framentec.fr 
Association Francaise des Utilisateurs d'Unix, France, doduc@afuu.fr

ilan343@violet.berkeley.edu (09/27/90)

In article <128@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes:
>There are now three sources of plug-compatible coprocessors.  (The
>Weitek is faster and more expensive, but it's not plug-compatible --
>you need a special socket [or adapter board] and special software to
>use it.  Standard 80287/80387 code can't use it.)
>
>
>Cyrix makes clones of both the 80287 and 80387.  These are slightly
>faster than Intel's parts and a little bit cheaper.
>
>IIT also makes clones of bothe the 80287 and 80387.  These are a
>good bit faster than Intel's parts for about the same price.

I have seen adds for Cyrix FastMath coprocessor (80387 compatible) that
claims 3X speedups.  Are there any benchmarks to support this?
Also, is compatibility an issue?

davidsen@sixhub.UUCP (Wm E. Davidsen Jr) (09/30/90)

In article <1990Sep27.060417.23408@agate.berkeley.edu> ilan343@violet.berkeley.edu writes:

| I have seen adds for Cyrix FastMath coprocessor (80387 compatible) that
| claims 3X speedups.  Are there any benchmarks to support this?
| Also, is compatibility an issue?

  I believe that was at 25MHz, but not 33MHz. Intel seems to have
changed the mask in the 33MHz version, so that it is faster by a good
bit. I believe several tests have shown this, including the recent one
in either _PC Week_ or _Info World_. I have been told that putting the
33MHz version in a 25MHz system will be about 40% faster, due to some
instructions taking fewer cycles. The people who told me this believed
it enough to buy the fa$ter part.

  This may be the only case where putting in a faster *rated* part
actually made the system faster without changing the operating speed.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me

amichiel@rodan.acs.syr.edu (Allen J Michielsen) (09/30/90)

>In article <1990Sep27.060417.23408@agate.berkeley.edu> ilan343@violet.berkeley.edu writes:
>| I have seen adds for Cyrix FastMath coprocessor (80387 compatible) that
>| claims 3X speedups.  Are there any benchmarks to support this?
>| Also, is compatibility an issue?
 
   At risk of starting a flame fest (pump, pump, pump, light)....
When cyrix (or anyone) claims a 3X or whatever speedup with stuff og this type
they REALLY are saying (in this case) that the average (or some measure)
80x87 instruction is performed in 1/3 the number of clock cycles.  To you
as a user, you will see virtually NO difference (generally) once the entire
system is assembled.  A typical application such as lotus or autocad does
use the 80x87, but a. the instruction mix they use almost certainly doesn't
line up with the one the claim was made using, & b. the stream of 80x87
instructions is intermixed.  For 1 80x87 instruction, there may be 50 or
100 80x86(8) & memory:I/O related instructions.   Using this model, with
the original claim, and some wild ass extrapolations, it should be clear
that while the 80x87 is important, just popping one in (or changing it)
won't ever lead to ANYTHING even remotely approaching nX speed ups.
   As a matter of fact, with lotus and any speadsheet I have (distributed
or my own), the difference with or without a 80x87 is som small I can't
even measure it.  On the other hand, in autocad, the difference between
with and without a 80x87 can be signifigant and easily measured. But this
number is much bigger (by a signifigant factor) than that even remotely
possible with a more effecient 80x87.
   Further, in a followup post to this original, one MAY get the idea
that more performance can be achieved by simply popping in a faster
chip speed in a slower socket.  This is NOT the case, the actual system
clock speed is like a traffic cop. Everything goes that speed in that system.
So, when a 100 Mhz chip is put in a 4.77 Mhz system, it will give very very
very nearly exactly the exact same performance as the same model chip with
a 4.77 Mhz rating. (There can be a terribly small differences but they
are so small it is nearly impossible to measure.)  In this case, the 
reference being made is to a fundamental change in chip design. This
change was implemented at a higher speed rating, and is responsible for
a measureable performance increase if/when that chip is used in a slower
system.
   It also is my understanding that the redesign of the 80387 chip by
intel that was implemented at the 33 Mhz speed, has been reapplied
across the board to all 80387's now in porduction.  Can anybody give
reference to either confirm or deny that rumour ?  (Anybody listening
at intel ?  --  I guess silence may be a answer also...)
al

--
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
 Bitnet: AMICHIEL@SUNRISE 

davidsen@sixhub.UUCP (Wm E. Davidsen Jr) (10/01/90)

In article <1990Sep30.160127.3442@rodan.acs.syr.edu> 
	amichiel@rodan.acs.syr.edu (Allen J Michielsen) writes:

|    At risk of starting a flame fest (pump, pump, pump, light)....
| When cyrix (or anyone) claims a 3X or whatever speedup with stuff og this type
| they REALLY are saying (in this case) that the average (or some measure)
| 80x87 instruction is performed in 1/3 the number of clock cycles.  

  Right. I haven't seen a claim that high, but that's how they get
their faster. I have seen notes that certain chosen instructions were
3X faster, but not even a claim that the overall performance was that
much better.

| as a user, you will see virtually NO difference (generally) once the entire
| system is assembled.

  That depends on your use and applications.

|                       A typical application such as lotus or autocad does
| use the 80x87, but a. the instruction mix they use almost certainly doesn't
| line up with the one the claim was made using, & b. the stream of 80x87
| instructions is intermixed.  For 1 80x87 instruction, there may be 50 or
| 100 80x86(8) & memory:I/O related instructions.   Using this model, with
| the original claim, and some wild ass extrapolations, it should be clear
| that while the 80x87 is important, just popping one in (or changing it)
| won't ever lead to ANYTHING even remotely approaching nX speed ups.

  I agree that those applications are not going to notably benefit. I
disagree that these are typical. I would claim that there simply is *no*
typical application today (if there ever was) and that basing any claim
for or against the need for additional hardware is either foolish or
misleading, depending on whether you believe it yourself.

|    As a matter of fact, with lotus and any speadsheet I have (distributed
| or my own), the difference with or without a 80x87 is som small I can't
| even measure it.  On the other hand, in autocad, the difference between
| with and without a 80x87 can be signifigant and easily measured. But this
| number is much bigger (by a signifigant factor) than that even remotely
| possible with a more effecient 80x87.

  I agree completely, for these applications you would see little
improvement from a faster math chip. You would se some, particularly if
you did a lot of transcendental functions, but not much.

|    Further, in a followup post to this original, one MAY get the idea
| that more performance can be achieved by simply popping in a faster
| chip speed in a slower socket.  

  I hope you get that idea, that's what I said.

|                                     This is NOT the case, the actual system
| clock speed is like a traffic cop. Everything goes that speed in that system.

  You were right a few paragraphs back. The better chips perform the
operation in fewer cycles. Therefore they do more operations in the same
time, or run the same program in less time. Without a change in clock
speed. Your first statement was correct, this one is wrong.

| So, when a 100 Mhz chip is put in a 4.77 Mhz system, it will give very very
| very nearly exactly the exact same performance as the same model chip with
| a 4.77 Mhz rating. (There can be a terribly small differences but they
| are so small it is nearly impossible to measure.)  In this case, the 
| reference being made is to a fundamental change in chip design. This
| change was implemented at a higher speed rating, and is responsible for
| a measureable performance increase if/when that chip is used in a slower
| system.

  As I read it, you just corrected yourself. If you use a redesigned
chip at the same speed it can run programs in fewer cycles (= less
time). I have seen some real programs (ie not benchmarks) which ran 25
times faster with a coprocessor. I make no claim that these are typical,
but while 100 sec is a lot better than 2500 sec (that's the ballpark for
this program), knocking 30% off that is going to be quite useful. I will
believe the 3X when and if I see it. I have seen figures taken by
someone who traded a 387 for an IIT and got about that 30%.

  Examples of programs which might do this kind of thing are star
charts, ray tracing, and calculation of complex orbits. There are people
who do that kind of thing, even for fun. Also fractals if float is being
used.

|    It also is my understanding that the redesign of the 80387 chip by
| intel that was implemented at the 33 Mhz speed, has been reapplied
| across the board to all 80387's now in porduction.  Can anybody give
| reference to either confirm or deny that rumour ?  (Anybody listening
| at intel ?  --  I guess silence may be a answer also...)

  I have no more solid information than you. My pet rumor says the
process and masks for the 25MHz has higher yield and therefore is still
in use for the chips which are slower rated. Note I have no more
confirmation than you, and if I get it it will probably be under
non-disclosure and I couldn't say so anyway.

  There are applications which benefit from 860s and vector processing
boards. Every user must be quite careful to understand what resources
s/he uses before buying hardware to provide more of same. On that I
agree with you completely and without reservation. I usually stop there
trying to tell someone else what will and won't be effective.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me

amichiel@rodan.acs.syr.edu (Allen J Michielsen) (10/04/90)

...
I wrote several ago... that I thought that the improvement to the
80387 chip mask, which increased the 'effeciency' of production per
clock tick --  which basically had been a side effect of producing
a 33 Mhz model, had been been implemented across the board and that
all intel 80387's had now received this 'improvement'.
(Not a quote but the basic gist of it...)
Per PCWEEK 10/1/1990 pg 4.
Intel Soups up 387 Coprocessor
(reprinted with out permission, and edited by me for brevity...)
... will be shipping 16, 20 & 25 Mhz versions ... as much as 20% faster...
.... by use of enhanced microcode....  List price, 16 Mhz $ 570 (Quan 1)
20 Mhz $ 647 (quan 1),  25 Mhz $ 814 (quan 1).
Hope this clears it up.  It isn;t clear that the old verison
is either going to be discounted heavily (although the price has been
dropping on the street) or discontinued...
al



--
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
 Bitnet: AMICHIEL@SUNRISE