Anonymous Coward wrote:

they were mass produced.

It isn't how many were made, it's how many survive. Finding the top speed rated Cyrix/IBM/ST 5x86 chips isn't that easy even though finding the 100mhz chips is.

rgart wrote:

I think most people would use a fsb of 33mhz and a multiplier of 4. Im not sure what boards can be modded to run with a 66mhz fsb stably other than the biostar mb8433

I'm not entirely certain if all of them support a 4x multiplier. I know that the Cyrix 120 chips were available with and without it. I'm not sure why because I have yet to see a 486 motherboard with 30mhz bus where you could use the 4x multiplier to make 120mhz. I run my 120 4x chip at 40mhz x 3 instead.

sliderider wrote:

I'm not sure why because I have yet to see a 486 motherboard with 30mhz bus where you could use the 4x multiplier to make 120mhz. I run my 120 4x chip at 40mhz x 3 instead.

What happens when you try to run your Cyrix 5x86-120/4x at 33x4 and 3.6 or 3.7 V? Some motherboards had native 3.6 and 3.8 V jumper settings.

Perhaps Cyrix was hoping some OEM's would swap out the standard 14.318 MHz motherboard crystal for a 12.88 Mhz (or whatever cyrstal frequency corresponds to the onboard clock generator's various multiplier settings) to allow for 30 Mhz.

The only natural 30 MHz FSB motherboards I am aware of were the ones made for the Cyrix MediaGX.

feipoa wrote:

What happens when you try to run your Cyrix 5x86-120/4x at 33x4 and 3.6 or 3.7 V? Some motherboards had native 3.6 and 3.8 V ju […]
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sliderider wrote:

I'm not sure why because I have yet to see a 486 motherboard with 30mhz bus where you could use the 4x multiplier to make 120mhz. I run my 120 4x chip at 40mhz x 3 instead.

What happens when you try to run your Cyrix 5x86-120/4x at 33x4 and 3.6 or 3.7 V? Some motherboards had native 3.6 and 3.8 V jumper settings.

Perhaps Cyrix was hoping some OEM's would swap out the standard 14.318 MHz motherboard crystal for a 12.88 Mhz (or whatever cyrstal frequency corresponds to the onboard clock generator's various multiplier settings) to allow for 30 Mhz.

The only natural 30 MHz FSB motherboards I am aware of were the ones made for the Cyrix MediaGX.

I'm not so sure I want to overclock this one and risk burning it up as 120mhz with 4x multiplier is the more difficult to find of the two 120mhz variants and we discussed in another thread that this particular chip is also unusual in the date that it was manufactured and the fab that it came from.

Most likely all the 30MHz 486 boards were used in OEM boxes, probably using proprietary form factors. I am almost certain Compaq was one of them. Remember AMD has a 90MHz 486 chip out there, 30MHz bus was the real deal.

How long have you had a 120MHz/4x?

CPU:120
FSB: 60
Multiplier:2
Voltage: 3.45
Video: Matrox Millenium
OS: Windows 98 SE with Service Pack 2.1a

Ok....So my CPU does not support a 4x multiplier.

I have another problem!

Whenever I turn on Branch Predicition and FP_Fast and then load windows 98...The mouse cursor appears very squashed and the mouse will not move further than about half way down the screen... The screen and icons look fine but the mouse will not move any lower.

As soon as I turn branch prediction off it goes back to normal... Any ideas?

Here the cursor is squashed...And where the mouse cursor is now I cannot move it further down.

Then as soon as I turn all cyrix enhancements off.
Mouse cursor back to normal.

You should only be enabling/disabling Cyrix features within DOS, prior to loading Windows. Confirm all of which features function at 3x33 (100 MHz) before moving onto 2x60.

feipoa wrote:

You should only be enabling/disabling Cyrix features within DOS, prior to loading Windows. Confirm all of which features function at 3x33 (100 MHz) before moving onto 2x60.

Ok: Yes I am using the Peter Moss utility in the command line of Autoexec.bat BEFORE windows loads.

And all I am doing is turning branch prediction and fp fast on.

Im NOT turning them on once windows loaded.

I haven't run into this mouse cursor miniaturization issue before.

BWRT and LINBRST are enabled by default with this motherboard. Disable these features. Were they disabled? I recall BWRT doesn't work well with s1r3.

Set LSSER to 0. I'm not sure if Peter Moss refers to a LSSER of 0 as enabled or disabled. This is the only feature which needs to be set to 0 to enable the enhancement. All others are set to 1 to enable the enhancement. Sometimes certain features conflict with other features, so you cannot assume that just because BTB=on causes mouse distortion that the issue is entirely related to BTB. A good example of this is that LOOP and RSTK work fine by themselves, BTB works fine on its own, but BTB, RSTK, and LOOP cannot all be enabled at the same time.

Once these 3 features are setup as indicated above, compare the Cyrix 5x86-100/3x to the IBM 5x86-100/3x with BTB and FP_FAST enabled before testing at 120 MHz.

No BWRT and LINBRST were enabled. I will disable them and try again.....

I always keep LSSER on 0. But your right. I guess Im thinking /lsser=off should be disabled 😜

I basically used Peter Moss's utility to enable BTB and fp_fast and Disable loop, lsser, rtwk. thats all I did.

If I cant get windows 98 stable soon Ill drop it back to 33mhz FSB x 3 and work from there like you have suggested.

Im hoping the issue Im dealing with is mainly software related so I have thrown it in a case for now.... and Ill keep at the software side of things until im frustrated enough to drop the FSB 😜

Heres the full tower case. I really love this full tower!

All the white in that case seems to match very nicely! I don't see many towers that tall with a MHz display.

Hey Feipoa!!

I found a Cyrix 5x86 133.. Cyrix 5x86 133 + a 3.6volt evergreen adapter

I now have a new purchase.

whooo hooo 😜

So maybe Evergreen is the company who got all the 5x86-133/4x chips. This is the first real example I've seen of one in the flesh from a CPU upgrade company.

Does it work? What is the stepping/revision? If you use it on the evergreen module, set the motherboard to 5V. If you use the chip without the upgrade module, set the voltage to 3.65 V.

EDIT: I wonder what that IC on the bottom surface of the Evergreen module does? I wonder if it sets CPU registers based on what motherboard the chip is installed in?

If you look at this page the cyrix evergreen 5x86 pga chip looks the same as rgarts, http://homepage3.nifty.com/sandy55/Interposer … interposer.html , I think the best hope for getting a cyrix 5x86-133 is to sneakily purchase one of these evergreen upgrades and hopefully the seller assumes its an amd chip, then again im/we(re) spilling these secrets over a public forum.....

feipoa wrote:

So maybe Evergreen is the company who got all the 5x86-133/4x chips. This is the first real example I've seen of one in the flesh from a CPU upgrade company.

Does it work? What is the stepping/revision? If you use it on the evergreen module, set the motherboard to 5V. If you use the chip without the upgrade module, set the voltage to 3.65 V.

EDIT: I wonder what that IC on the bottom surface of the Evergreen module does? I wonder if it sets CPU registers based on what motherboard the chip is installed in?

I'll get back to you on the stepping/revision..

http://ec1.images-amazon.com/media/i3d/01/A/m … AL000017863.pdf

http://web.archive.org/web/20000815062705/htt … ertech.com/586/

Dirkmirk, I don't think many Evergreen upgrades with a Cyrix 5x86-133/4x were available. I searched for a few years during the prime time of surplus and cheapness - 2000-2004, but never found one with a 133/4x.

That Evergreen upgrade manual was overly simplistic. It didn't even make mention of their own Evergreen Cyrix 5x86 bit enabler program.

Im by no means an expert on evergreen 5x86-133 cpus, surely theirs only two cpu types for the evergreen cpus, the pga cyrix 5x86 and the pqfp amd 5x86, that cyrix 5x86 adapter has vertical jumpers and the amd is horizontal, If I ever see one of those pga type evergreen upgrade cpus im going to be all over it like a fly on shit, in the link I I posted above the two adapters appear almost exactly the same and the amd adapter is clearly different.

rgarts

link of other evergreen cyrix adapter

evergreen amd style

Anonymous Coward wrote:

Most likely all the 30MHz 486 boards were used in OEM boxes, probably using proprietary form factors. I am almost certain Compaq was one of them. Remember AMD has a 90MHz 486 chip out there, 30MHz bus was the real deal.

How long have you had a 120MHz/4x?

Probably about 6 months to a year. Believe it or not, I found it in one of those scrap gold lots with a AMD DX4 120 and two AMD DX4 100's. and I also found the Biostar motherboard that it is installed in in a separate scrap gold lot. There's a lot of rare stuff out there that is going to waste being sold for scrap.

Weird. I've been keeping an eye on evergreen adapters on ebay for years and never saw anything that even remotely resembled that. They were always the PQFP am5x86 type.

This one looks like it has burnt pins. I wouldn't put much faith in it's functionality.