Cyrix 386 -> 486 upgrade chip: Will this work?

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Iris » Sat, 06 May 1995 04:00:00



        That's it: I'm getting a Cyrix upgrade chip (cheep) for my
386dx25, and I'm wondering if it'll work. Someone told me the internal
cache has to be turned on via a software driver; is there one for Linux
(hah)? Will there be any other hassles? Is this worth it? I'm only paying
US$50 for it, and I can resell it if it bombs completely.....

        Thanks for any info you care to share,
--
                 T \ /

                 A / \

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Iris » Sun, 07 May 1995 04:00:00


>    sunsite.unc.edu:/pub/Linux/...
>    There is a cyrix enabler there.
> --


        Many, many thanks!

        Irish

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Timothy Murp » Mon, 08 May 1995 04:00:00



>>        There is a cyrix enabler there.
>    Many, many thanks!

What is the Cyrix upgrade chip, as a matter of interest ?
Can it replace any 386 ?
How much does it cost ?

--
Timothy Murphy  

tel: +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Sean A. Lo » Mon, 08 May 1995 04:00:00


: What is the Cyrix upgrade chip, as a matter of interest ?
: Can it replace any 386 ?
: How much does it cost ?

I got a motherboard (386) that had ami bios with cyrix DLC detection and cache
enable built in... came with 128 k cache...

The 486DLC-40 costs about $80, the clock
doubled 486DRx2 33-66 costs $250 or so.

It is painless except older motherboards didn't
have the zero-insertion-force chip sockets
so getting the chips in and out can be
dangerously difficult.  There are cache enabling
utilities for both DOS and linux if your
motherboard can't figure it out by itself.

Sean Long

--

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Iris » Mon, 08 May 1995 04:00:00



>: What is the Cyrix upgrade chip, as a matter of interest ?
>: Can it replace any 386 ?
>: How much does it cost ?

        As the initiator of this thread, let me tell you what I now know.
Cyrix makes (among other thing, I'm sure) a variety of upgrade chips for
virtually all 386es (seems like). Pull your old one out, stuff this one
in, and WaaLaa! 486. A lot of them double the CPU clock too, so if you
have a 25MHz 386, it'll be a 50MHZ 486. I believe there is even one for
those soldered in SXes too; fits over the top. Anyway, the other issue is
a 386 MB has no way to turn on the internal cache of a 486 (done in the
hardware of a 486 MB), so it has to be done via software. Here's the Cool
Bit; the software is GPLed. Free. Even for the DOS versions. Naturally,
there is a Linux version on Sunsite.

        Here's what I've noticed so far in performance: Major
Improvement. Well worth the cash if a real 486 is out of your reach. I
haven't run any benchmarks or anything, this is purely subjective, but I
also just built a i486dx33 (clocked to 40), and there isn't much
difference between it and my 486DRx2 50 (386 25MHz MB w/Cyrix upgrade).
The only real drawback that I can see is there's no VLB on 386es, so
you're limited at the bus, but other than that I'm very happy with it.

        As far as price, it'll vary with the chip you need for your MB,
but I think they are averaging ~US$150. I got mine for $50 used.

        Hope that helps,
--
                 T \ /

                 A / \

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Ed Runni » Tue, 09 May 1995 04:00:00




>>: What is the Cyrix upgrade chip, as a matter of interest ?
>>: Can it replace any 386 ?
>>: How much does it cost ?
>    As the initiator of this thread, let me tell you what I now know.
>Cyrix makes (among other thing, I'm sure) a variety of upgrade chips for
>virtually all 386es (seems like). Pull your old one out, stuff this one
>in, and WaaLaa! 486. A lot of them double the CPU clock too, so if you
>have a 25MHz 386, it'll be a 50MHZ 486. I believe there is even one for
>those soldered in SXes too; fits over the top. Anyway, the other issue is
>a 386 MB has no way to turn on the internal cache of a 486 (done in the
>hardware of a 486 MB), so it has to be done via software. Here's the Cool
>Bit; the software is GPLed. Free. Even for the DOS versions. Naturally,
>there is a Linux version on Sunsite.
>    Here's what I've noticed so far in performance: Major
>Improvement. Well worth the cash if a real 486 is out of your reach. I
>haven't run any benchmarks or anything, this is purely subjective, but I
>also just built a i486dx33 (clocked to 40), and there isn't much
>difference between it and my 486DRx2 50 (386 25MHz MB w/Cyrix upgrade).
>The only real drawback that I can see is there's no VLB on 386es, so
>you're limited at the bus, but other than that I'm very happy with it.
>    As far as price, it'll vary with the chip you need for your MB,
>but I think they are averaging ~US$150. I got mine for $50 used.
>    Hope that helps,
>--
>             T \ /

>             A / \

For some figures :

My old 386/20 MB with the 486/40 DrX2 : ~13 BogoMIPS
the 486 DrX2, without the cache enabled : 4.73 BogoMIPS
the board with the 386 in it : I am NOT a glutton for punishment
My 486/66 VLB/PCI : 33.55 BogoMIPS

As you can see, it helps but it still isn't a 486 by a long
shot.  And the bus limiting factor is bigger than you think,
especially in X.  Went from a slug with the DrX2 and a Trident
8900 ISA to pretty damn fast indeed with the 486/66 and
ET400/W32p VLB.  

--
Ed Runnion - Center for Semiconductor Device Reliability Research
Clemson University, MS EE, Clemson SC USA    Office : 104 Rhodes

Web Homepage : http://www.clemson.edu/~erunnio/ed.html

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Iris » Wed, 10 May 1995 04:00:00



>For some figures :
>My old 386/20 MB with the 486/40 DrX2 : ~13 BogoMIPS
>the 486 DrX2, without the cache enabled : 4.73 BogoMIPS
>the board with the 386 in it : I am NOT a glutton for punishment
>My 486/66 VLB/PCI : 33.55 BogoMIPS
>As you can see, it helps but it still isn't a 486 by a long
>shot.  

        When you consider what 'BogoMIPS' stands for, I'll take it with a
grain of salt and wait for an actual benchmark test. When I posted
originally, I had about an hour total on each machine. Still speaking
subjectively after a couple of days of use on each one, The i486 IS
faster than the Cyrix by a fair bit, BUT the difference between the
(original) 386 and the Cyrix is quite significant.

Quote:>And the bus limiting factor is bigger than you think,
>especially in X.  Went from a slug with the DrX2 and a Trident
>8900 ISA to pretty damn fast indeed with the 486/66 and
>ET400/W32p VLB.  

        Well of course! My two machines are closer in speed than yours (I
know, MHz isn't everything), but there is still a difference between
them. Plus, I'm still using my ISA card in the VLB machine, even closer
yet, still a difference. But both are *much* faster that the workstation
I farmed out -- a 386sx20. Now there's some pain...

        The point is if for whatever reason you can't get a real 486, the
Cyrix is worth it, and does just fine under Linux/X.

--
                 T \ /

                 A / \

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by liuy » Thu, 11 May 1995 04:00:00




>: What is the Cyrix upgrade chip, as a matter of interest ?
>: Can it replace any 386 ?
>: How much does it cost ?
>I got a motherboard (386) that had ami bios with cyrix DLC detection and cache
>enable built in... came with 128 k cache...
>The 486DLC-40 costs about $80, the clock

You can get a new 486dlc-40 for under $50 last time I check in computer
shopper.  A used one should be $30 or less.
 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Timothy Murp » Fri, 12 May 1995 04:00:00



>>I got a motherboard (386) that had ami bios with cyrix DLC detection and cache
>>enable built in... came with 128 k cache...
>You can get a new 486dlc-40 for under $50 last time I check in computer
>shopper.  A used one should be $30 or less.

But can this just replace a 386 chip ?

--
Timothy Murphy  

tel: +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Martin Casse » Sat, 20 May 1995 04:00:00



Organization: Planet Access Networks - Stanhope, NJ
Distribution:


= >But can this just replace a 386 chip ?

=       In a word, yes. The exact chip you need will depend on what
= you're replacing (and how much you want to spend), but in most cases
= simply yank the 386 chip out and stuff the Cyrix 486 chip in. Get and run
= the caching software (it is NOT a kernel patch, it runs in user-space and
= is started from an rc boot-time file), and you're done.

Would you elaborate on the caching software... what it does and why it's
necessary for the Cyrix 386-->486 chip to work.
thanks
--

--                                              
Some painters transform the sun into a yelow spot;
others transform a yellow spot into the sun. -- Pablo Picasso

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Henry Wert » Sat, 20 May 1995 04:00:00



Cassel ) writes:

>Organization: Planet Access Networks - Stanhope, NJ
>Distribution:

*cut*

>Would you elaborate on the caching software... what it does and why it's
>necessary for the Cyrix 386-->486 chip to work.
>thanks

     Yes.  On 486's with onboard cache, the cache is automagically turned on
by the BIOS.  You put a 386-->486 chip on your board, it's still got a 386
BIOS that knows nothing about enabling caches.  So, the cache is enabled by a
program instead 8-).  It isn't necessary for the 486's functioning, but it
speeds it up considerably.

>--

>--                                              
>Some painters transform the sun into a yelow spot;
>others transform a yellow spot into the sun. -- Pablo Picasso

---

for this .sig 8-)
It's reported that Canter & Siegel search for and archive all articles
that contain their names or "Green Card".  This .sig is to help them.  

 
 
 

Cyrix 386 -> 486 upgrade chip: Will this work?

Post by Iris » Sat, 20 May 1995 04:00:00





>= >But can this just replace a 386 chip ?
>=   In a word, yes. The exact chip you need will depend on what
>= you're replacing (and how much you want to spend), but in most cases
>= simply yank the 386 chip out and stuff the Cyrix 486 chip in. Get and run
>= the caching software (it is NOT a kernel patch, it runs in user-space and
>= is started from an rc boot-time file), and you're done.
>Would you elaborate on the caching software... what it does and why it's
>necessary for the Cyrix 386-->486 chip to work.

        Certainly. It isn't /necessary/ for the chip to function, i.e.
it'll process instructions without it, BUT it'll be much slower. One of
the primary advantages the 486 has over the 386 is an internal cache that
works much like the cache on your hard drive, only it's for processor
instructions. In real 486 hardware this cache is 'turned on' by the MB at
power-up via a pin on the chip. A 386 MB has no such circiutry, since a
386 chip doesn't require it. So what the software does is send a signal to
the Cyrix chip via the existing 386 MB circuitry that 'turns on' its
cache. This makes it work *much* faster, but as I said, it isn't required
for the chip to function. In fact, I put my chip in, booted Linux/X, made a
SLIP connection, FTPed in the software and /then/ set it up and enabled
it. There was a vast improvement afterward, but beforehand it felt like a
slightly faster 386.
        The software (in Linux) is started at boot-time by placing the
command in one of your /etc/rc.d files (rc.local, for instance). I mention
this only because several people erroneously informed me that it was a
kernel patch (can you say re-compile? I knew you could!) when I first
inquired about it. The docs on the software are pretty clear though, and I
think it would be rather difficult for the average user to patch a DOS
kernel on M$ based machines anyway. BTW, the software for both Linux AND
DOS is GPLed -- free for the finding and source code included (really,
even the DOS version). Now there's something GNU :)

--
                 T \ /

                 A / \