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Grex Micros Item 90: 386 20mhz Active Matrix-$1100 --good deal?
Entered by matts on Thu Jun 2 21:05:42 UTC 1994:

i found leading edge 386 20mhz active matrix notebooks
for $1100!  is this too high. i phigured that  it was 
worth is just for the screen.  is there any one who has
seen this particular brand of nonotebook, or this model?
is there any way of uping it's preformance?  like i have
seen the converters for 286 to make it
a 386, but is there somehitng out there for a 386.  if
oso , any idea if it would work on a notebook?

13 responses total.

#1 of 13 by dam on Sat Jun 4 01:56:14 1994:

sounds used or abused or something.

386sx or even dx 20 - why would such a cheapcpu be put with 
an active matrix screen?  

I think it would be very difficult to upgrade this cpu - notebook
motherboards are not the same as motherboards for chassis - it most likely
uses a surface mount chip for space.  yep, every millimeter counts...

but, if it was socketed, Cyrix makes 486 "compatable" chips for both
386 sx and dx boards, called th e Cyrix 486 slc and dlc respectively.
I think.  they might have shoved some other silly letters in there
somewhere to make it look different from AMD's slc and dlc chips.
anyway.  the point is you get this chip, plug it into your 386, and
instant 486.  kinda.  there is a program to run in your autoexec
or somethng that turns on the cyrix cache too for more speed.

#2 of 13 by matts on Sat Jun 4 02:08:42 1994:

any idea at all of how fast a 386 20 is?  how would it compare to my
486dx2?  i know it would be slower...but how slow....

#3 of 13 by mju on Sat Jun 4 09:29:19 1994:

A 486 runs roughly twice as fast as a 386 running at the same clock
speed.  A 486DX2 again runs roughly twice as fast as a 486DX
running at the same base clock rate.  So a 486DX2/20 would be
four times faster than a 386/20.  Your DX2 is a 66, so that
makes it roughly three times faster than the 486DX2/20.  So,
the 386/20 would be about 12 times slower than the 486DX2/66.

#4 of 13 by matts on Sat Jun 4 14:53:49 1994:

okay, but for standard operation, as is using windows, dos, etc, how 
slow would it really be?  My computer mainly is limited by hard drive
speed, not the speed of the processor.  I guess what i am asking it 
how slow would it seem to use.  I plan on using it for games and 
word processing, and that's about it..

#5 of 13 by bdp on Thu Jun 9 17:15:28 1994:

Depends on what kind of applications you run with Windows - as long as you keep
it simple, you should be okay.  Windows isn't too bad on an SX - I know,
because I used it at one point on my old 386sx-16.

#6 of 13 by dam on Mon Jun 27 01:33:57 1994:

I think there are a few other things to think about re: how much
faster a 486dx2/66 is to a 386sx/20.

the sx has no math coprocessor.  some of the new fangled games would make
good use of that. 

the sx has no cache memory!  a 64k external cache on a 486 (and I would
think your 486dx2/66 has at least 128k) is good for a 150-175% performance
increase alone.

the 486 also has an internal cache.  very fast.

if the program can take advantage of the special extended 486 instruction
set, it will go faster.

#7 of 13 by jshafer on Sat Sep 24 05:54:31 1994:

Re #1: So this add for a notebook with a Cyrix 486SLC-33 CPU is really 
a reworked 386?  And, do you think that it would be worth $1000 for, 
with only 2Mb RAM included, but w/ a 120Mb hard drive?  (It's also 
got a 9.5" mono VGA screen.)
I have no experience with notebooks, so any comments or tips would be
helpful.

#8 of 13 by raven on Sat Sep 16 05:40:57 1995:

        Are those Cyrix 486 chips still available?  I have a Dell 386
sx 40 with a math-co thAT I would like to upgrade to 486.  Also any idea
of the price on those chips.

#9 of 13 by scott on Sat Sep 16 12:21:43 1995:

MicroSystems Warehouse (800-660-3222)
has a Cyrix upgrade for about $200, but the chart only covers 386 speeds up
to 25MHz.  Is your 386 clock doubled or just run fast?  The Cyrix chips
appear to run at clock-doubled 50MHz, for a motherboard speed of 25MHz.

#10 of 13 by scg on Sat Sep 16 23:52:05 1995:

I'm not sure why you'd want to put a 486 chip on a 386SX motherboard.  The
486 has a 32 bit bus, while the 386SX has a 16 bit bus, so it would be a lot
faster to use a real 486 motherboard.

#11 of 13 by scott on Sun Sep 17 00:17:16 1995:

A new 486 motherboard from the same catalog with a DX2/66 lists for $300,
and has some 30-pin memory slots along with 2 72 pin slots.  The main problem
with changing motherboards from 386 to 486 is usually memory compatibility,
although the 30 pin slots on this example might solve that.

#12 of 13 by raven on Sun Sep 17 04:11:51 1995:

        Yes but the question can I get a new motherboard for a 1992 Dell
notebook?

#13 of 13 by scott on Sun Sep 17 12:59:51 1995:

Ooop - sorry, thought this had drifted into "expansion in general".

You are probably hosed for getting an updated motherboard, and also hosed for
getting any kind of "upgrade" processor in place.  Because of size
restrictions, notebooks are a hell of a lot harder to update than desktops.

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