vmr_ wrote on 2023-11-30, 15:01:

Same goes for MII 350 - seen so few of these - guess production was very limited.

The production MII-pr350 required a 90mhz FSB and thus only worked with one motherboard .

They (IBM) designed all MII/6x86mx above pr300 and quickly moved to 83mhz fsb (pr333) once nobody standardized to that 90mhz fsb and Cyrix eventually went to 95/100mhz FSB for pr366+ on chips labled with their namesake, strangely IBM was more heavily involved in Cyrix after the agreement/ partnership dissolved then they were before

As for 8087, the primary difference between the golden original and later 287+ examples was that the original 8087 had an mmu of sorts and could fetch its own data, this made it somewhat faster clock for clock than a normal 287 or 387

My first computer was a panasonic desktop, 8086 and i think it was 4mhz

Used it a lot but I hated it because of the CGA monitor, normally i would go to visit some friends who had PCs with EGA monitors in their homes, one even had an ibm PS/2, then i would come back to my house and hate my CGA monitor.

If i ever see one of those cga monitors in the trash on the street i would just give it my middle finger.

In 1994 i was able to make the big upgrade, had to buy the cheapest possible new pc. And that was a no brand, no brand vga monitor, clone pc, generic case, generic mouse and generic keyboard, that PC had a cyrix 486 dx2 66mhz. Finally i was able to enjoy what i think was the first master race PC i had in my life. Spent so much time playing DOS games that it would be impossible to list them all.

With that machine i enjoyed Windows 3.1, with that machine i installed my first soundcard/CD-rom kit from media vision Fusion in 1994, and with that machine i connected to the internet for the first time using windows 3.1 and trumpet winsock. and upgraded it with a trident vesa videocard and a 14,400 Fax modem.

Today i have one of those cyrix CPUs in storage it has a green heatsink

Fun times. Yah I've got two of the green sink ones around, DX2-66 and DX2-80. We're not collecting much DX2 info in this thread. The DX and DX2 seem to score high in whetstone FPU tests, the integer unit seems to lag intel/AMD though. I am considering the possibility that this might be motherboard chipset specific. Though the M919 has the highest degree of BIOS support for Cyrix in general, as do a handful of other late 486 boards, I think it's UMC chipset is in general not something that likes the earlier 486es much. I am looking around to see if I can get a sense of what's up. Not sure yet if there is a measurable difference, or whether it's some outliers.

Back in the day was running some tests of ST 486 against AMD 486 and the gap wasn't as bad as some charts I have seen recently, but I am unable to recall what chipset that was on. That was at dx2/66 speeds and was consistent lead for the AMD, but close enough that you wondered if it was quantisation errors rather than an actual 1 or 2%

My AST ADVENTURE ADVANTAGE 4/66D had a green Cyrix DX2-66 if it had a performance deficit it was under 5% even based on vintage benchmarks I ran at the time.

Where things become confusing is on the early socket 3 Cyrix “486” offerings, the early socket 3 chips were a different architecture and had wonky compatibility and performance issues which is likely where people gained the belief that there was a vast as opposed to a minor performance difference due to the 486s+dingus that took the place of a real 486dx.

By the time Cyrix had DX4-100’s there was very little in the way of compatibility or performance differences

I like the Cyrix era.It also turned out that with a good video card, it is also excellent in 3D, as the data transfer is fast, even though the FPU is weaker.

I probably like the black MII/300 the best.

400 gold is relatively rarer.

And the 5x86 row is also great in SPi, in the socket3 category.

Congrats for your collection. The 5x86 120 is truly a treasure, also the 400gp.
For sake of collection (or hoarding), I have 3 versions of the 333gp, the silver, the gold and the black top.

Nemo1985 wrote on 2024-02-22, 19:45:

Congrats for your collection. The 5x86 120 is truly a treasure, also the 400gp.
For sake of collection (or hoarding), I have 3 versions of the 333gp, the silver, the gold and the black top.

Thank you.
I congratulate you too! The 333 is also quite rare.

Man I wish I had scooped up more higher MII and 5x86 to play with while they were cheap.... though saying that, they never saw much action in the time between they were useful for last desperate upgrades and the retro interest... by action I mean that you wouldn't see them for sale anywhere.

BitWrangler wrote on 2024-02-22, 20:41:

Man I wish I had scooped up more higher MII and 5x86 to play with while they were cheap.... though saying that, they never saw much action in the time between they were useful for last desperate upgrades and the retro interest... by action I mean that you wouldn't see them for sale anywhere.

Maybe around 2010 there were even more, and cheaper if I remember correctly. However, PR400/433 was never common, and I didn't see Cx5x86 very often either.
I had so many advantages that I was lucky enough to get a lot of procs for free.
To your previous post: I favor 3 Socket3 motherboards:
FIC 486-PI03 PCI
Asus SIS471 VLB
Octek Hippo 15 PCI
The fastest cards for DX/DX2/4/5x86 series.

For example, in Hippo15 AMD5x86 runs 200MHz 😀

Thanks, I've got two of those Asus boards, will have to reserve one as VIP lounge Cyrix only.

The Cyrix 5x86-100 was a pretty common one. The -120 not so much. The -80 is pretty rare though, and yours is in excellent condition too. What kind of interposer is it using?

Anonymous Coward wrote on 2024-02-23, 01:52:

The Cyrix 5x86-100 was a pretty common one. The -120 not so much. The -80 is pretty rare though, and yours is in excellent condition too. What kind of interposer is it using?

Well, I don't know exactly, I think it's a converter/voltage regulator, I haven't tried it yet, but as you can see in the photo, I put the processor there. Not sure if it's specifically for the 80, it came with many processors. I'll take a look and take a close-up photo to find out its parameters.

I have two IBM branded 5x86-100s that both work fine at 120. Rumor is IBM picket 120s and labelled them as 100s? Regardless, I'm happy I got them when I did. Awesome chips. One of them is the core of my daily use 486 😀

Do you plan on leaving the labels on the CPUs? The presence of the labels may leave permanent discolouration on the ceramic over the years.

I was looking at your Cyrix 5x86-80GP and thought the font was a little off, like the '0' was remarked. This is what my 80 MHz chip looks like next to yours. Where did you obtain your 80 MHz 5x86? I suspect it was an unmarked Cyrix 5x86 and someone added the "5x86-80GP". What marking is on the bottom?

That's true about labels, anything I've had where there was a warranty or date sticker on the ceramic, it has had a dark patch underneath like something soaked into the ceramic.

feipoa wrote on 2024-02-23, 08:48:

Do you plan on leaving the labels on the CPUs? The presence of the labels may leave permanent discolouration on the ceramic over the years.

I was looking at your Cyrix 5x86-80GP and thought the font was a little off, like the '0' was remarked. This is what my 80 MHz chip looks like next to yours. Where did you obtain your 80 MHz 5x86? I suspect it was an unmarked Cyrix 5x86 and someone added the "5x86-80GP". What marking is on the bottom?
Cyrix_5x86-80_font.jpg

Labels were affixed by the previous collector. On 600+ CPUs, from my collection of 1000 pieces. I'll remove it when I have a lot of time.
The character is really different, have they already faked it here..?
Today I will find and take close-up photos of both the 80 and the converter, although it will not be easy to find among 1000 CPUs.
The posted photo was taken years ago.

appiah4 wrote on 2024-02-23, 05:33:

I have two IBM branded 5x86-100s that both work fine at 120. Rumor is IBM picket 120s and labelled them as 100s? Regardless, I'm happy I got them when I did. Awesome chips. One of them is the core of my daily use 486 😀

At that time, production line marking also worked here, according to what the market was asking for.

DarthSun wrote on 2024-02-23, 14:45:

appiah4 wrote on 2024-02-23, 05:33:

I have two IBM branded 5x86-100s that both work fine at 120. Rumor is IBM picket 120s and labelled them as 100s? Regardless, I'm happy I got them when I did. Awesome chips. One of them is the core of my daily use 486 😀

At that time, production line marking also worked here, according to what the market was asking for.

I did find in a data sheet or addendum one time where it said IBM had specified 35 micron on the interconnects and pin plating, where the cyrix sheet had 25, so some support for the "IBM branded CPU are better" theories. That particular thing means I think that there's a ~30% better heat path from the die through the pins, so given an equally capable chunk of silicon the IBM one will do a little better due to running a little cooler. Although I have also heard that IBM specified a higher quality of layering inside the die itself, but not seen the tech reference confirmations.

BitWrangler wrote on 2024-02-23, 14:58:

DarthSun wrote on 2024-02-23, 14:45:

appiah4 wrote on 2024-02-23, 05:33:

I have two IBM branded 5x86-100s that both work fine at 120. Rumor is IBM picket 120s and labelled them as 100s? Regardless, I'm happy I got them when I did. Awesome chips. One of them is the core of my daily use 486 😀

At that time, production line marking also worked here, according to what the market was asking for.

I did find in a data sheet or addendum one time where it said IBM had specified 35 micron on the interconnects and pin plating, where the cyrix sheet had 25, so some support for the "IBM branded CPU are better" theories. That particular thing means I think that there's a ~30% better heat path from the die through the pins, so given an equally capable chunk of silicon the IBM one will do a little better due to running a little cooler. Although I have also heard that IBM specified a higher quality of layering inside the die itself, but not seen the tech reference confirmations.

Cyrix is a small engineering team, brilliant. Then, which production line the designs were made on varies.
MII and 6x86MX were compared in my tests, MII is slightly faster...

DarthSun wrote on 2024-02-23, 14:38:

Labels were affixed by the previous collector. On 600+ CPUs, from my collection of 1000 pieces. I'll remove it when I have a lot […]
Show full quote

feipoa wrote on 2024-02-23, 08:48:

Do you plan on leaving the labels on the CPUs? The presence of the labels may leave permanent discolouration on the ceramic over the years.

I was looking at your Cyrix 5x86-80GP and thought the font was a little off, like the '0' was remarked. This is what my 80 MHz chip looks like next to yours. Where did you obtain your 80 MHz 5x86? I suspect it was an unmarked Cyrix 5x86 and someone added the "5x86-80GP". What marking is on the bottom?
Cyrix_5x86-80_font.jpg

Labels were affixed by the previous collector. On 600+ CPUs, from my collection of 1000 pieces. I'll remove it when I have a lot of time.
The character is really different, have they already faked it here..?
Today I will find and take close-up photos of both the 80 and the converter, although it will not be easy to find among 1000 CPUs.
The posted photo was taken years ago.

80 CPU front, rear, and after removing the label, front, left a mark, I cleaned it with a glasses wipe, but the remains are visible.

I can't find the converter yet, there is a motherboard and video card column in front of the corresponding accounts.