Retroinside wrote on 2025-05-09, 13:36:

Hi everyone, […]
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Hi everyone,

I made a video where I compare the AMD K6-2+ and the Intel Celeron Mendocino, both running at 600MHz (133MHz FSB x 4.5 multiplier) and with 128KB of full-speed L2 cache.

https://youtu.be/SiQtdPJzN8c

The idea was to bring the two platforms to the same level to eliminate possible bottlenecks between RAM and CPU, and to see if Socket 7 could still hold its own.

This setup is just an example of how we can still get decent computing power today from these old systems, but it made me wonder: what would’ve happened if 133MHz FSB had become standard on Socket 7? And what if AMD K6 CPUs could go beyond 600MHz?

Multipliers could go up to 6x, so in theory, 6x133 = 800MHz. If AMD had continued supporting Socket 7 with CPUs featuring 256KB of full-speed cache like the K6-III, maybe they could’ve reached performance levels close to same-clock Pentium IIIs. Sure, we all know about the limited AGP support and the platform’s other constraints, but perhaps chipset manufacturers could’ve made some improvements.

I hope to dive deeper into this topic in the future. For now, I can say that I own a K6-2+ modded to a K6-III+ that runs beyond 600MHz, and I can't wait to see what it can do — and eventually open the comparison to a Pentium III.

Let me know your thoughts!

Ciao 👋
I saw your video, and I subscribed to your channel, I wrote about the subject in the past, both here on Vogons and on other sites, unfortunately there is very little about it.
From what little I found, AMD had the K6+ CPUs with FSB 133 ready, and I think they were over 600 MHz, they had integrated L2 cache, and also the motherboard manufacturers, had released special MBs, with updated chipsets, without L2 cache (which then becomes L3), and some I think with integrated video, in short, everything was ready, but it never arrived on the store shelves 🏬
Why? It is said that it was the success of the Duron, to get the K6 out of production, probably it was also because of the transition to Socket A (462), those CPUs were cheaper than those Slot A, but only recently it was seen that the actual power of the K6-2-3, has never been used to the maximum, many software does not support 3DNOW! instructions, and in a recent video, it was seen that through a special program, recently updated, the results in many benches are better, a sign that at the time, maybe it was easier to use hw Intel, rather than updating the various software, And fully support the potential of the K6-2-3 chips.
Personally, I had both K6 and Celeron 370 CPUs, currently I have several, among the various PCs or motherboards in collection, I am currently working on the bench, with a Soyo SY-6BA+IV and Celeron Slot1 333 motherboard, I overclocked it up to 500 MHz, but at that frequency it freezes in some bench (of Phil's), while at both 450 and 475 (FSB 90 and 95), it works at least in DOS, I did not try in Windows because it should be installed, while with DOS I just have to move the memory card from one PC to another.
I also really like AMD's K6 CPUs, I have various versions, simple K6, K6-2 up to 550, K6-III from both 400 and 450 MHz, and a couple of K6-2+ (400 and 550), I also have some K5 that I find just as interesting 🧐, then various Cyrix-IBM up to 333 (262 MHz), and a couple of IDT C6-200, but I find the latter less performant than 🫡 to any Intel AMD Cyrix.

Hi there! 😊
Thank you so much for your support and for your wonderful comment , it’s such a huge pleasure to find someone else who appreciates the legendary Socket 7! 💾💖

The information you shared is truly fascinating, and some of it I honestly didn’t know , especially the part about AMD having more advanced K6 CPUs ready with a 133 MHz FSB, along with motherboards featuring updated chipsets and no onboard L2 cache (which would have effectively become L3). If you have any links, original sources from back in the day, or even more anecdotes, I’d be really curious to learn more!

Personally, I have a deep fondness for the AMD K6 series , they made me fall in love with their performance and unique architecture. I was born in 1994, so sadly I didn’t get to experience that golden era in real time… everything I know today comes from an endless passion for vintage hardware, fueled by curiosity and the joy of discovery.

And those CPUs you mentioned , the Cyrix chips, the K5… they’re all beautiful pieces of history, each with their own unique charm.
Your test bench with the overclocked Celeron 333 is super interesting too, I love reading about that kind of experimentation! Oh and P.S i love that SOYO BX Mobo! 😍

I’ll be more than happy to keep sharing new tests and deep dives on the channel to explore this amazing Socket 7 platform. Thanks again for sharing your experience, this is exactly the kind of spirit that makes the community so special! 🙌

I'm gonna watch this a couple of times - I'm actually trying to learn Italian (via Duolingo app) but hearing an actual Italian speaking Italian about a subject I know a bit about actually wins every time - and also it's an interesting setup 😀

Do you have a brief written summary (if only the final benchmark results) for people who hate getting technical info from videos?

English would be better for me, still results i looked and results are similar for K6-2+ and Celeron A @ 3DMark99 Max.

@H3nrik V!
I'm really glad to hear that the video might help you improve your Italian, that makes me happy! I'm actually doing the same,with other video creators, trying to improve my English, so it's nice to hear we're both learning something from this. 😄

Thanks also to everyone who's been commenting on this post, I really appreciate it.
I’ve actually tried making content in English before, but it’s quite challenging for me, both in terms of time and because I’m never fully happy with how I sound when I speak. Maybe one day I’ll try again!

@dionb
Unfortunately, I didn’t write a report or collect any screenshots, etc. Anyway, I’m definitely not saying you have to watch the video to see how it ends — not at all! Here's a quick summary:

Socket 7 Platform:
CPU AMD K6-2+
MB Freeway FW-TI5VGF (Chipset VIA MVP3)
DIMM SDRAM PC133 CL2 128MB
VGA Matrox G400
CPU-Z Vintage Bench: 1050.3 / 3826.3
3D Mark 99: 3785 / 8021

Slot 1 / PGA370 Platform:
CPU Intel Celeron Mendocino 300A
MB Soltek SL67KV (Chipset VIA Apollo Pro 133A)
DIMM SDRAM PC133 CL2 128MB
VGA Matrox G400
CPU-Z Vintage Bench: 963.7 / 4162.8
3D Mark 99: 3804 / 4935

Same O.S (Windows 98 SE) and same Driver for VIA chipset and Matrox VGA.

Thanks i have big interest in both platforms, but never have a chance to compare because dont have a + K6, will be good a doom/quake DOS benchmark

Thanks! I actually already plan to run some tests using Phil's benchmark collection, including DOOM and Quake. For that, I’ll push both CPUs to their maximum clocks. Under DOS, they’re stable at much higher frequencies and complete the benchmark without issues

Retroinside wrote on 2025-05-13, 07:27:

Hi there! 😊 Thank you so much for your support and for your wonderful comment , it’s such a huge pleasure to find someone else w […]
Show full quote

Hi there! 😊
Thank you so much for your support and for your wonderful comment , it’s such a huge pleasure to find someone else who appreciates the legendary Socket 7! 💾💖

The information you shared is truly fascinating, and some of it I honestly didn’t know , especially the part about AMD having more advanced K6 CPUs ready with a 133 MHz FSB, along with motherboards featuring updated chipsets and no onboard L2 cache (which would have effectively become L3). If you have any links, original sources from back in the day, or even more anecdotes, I’d be really curious to learn more!

Personally, I have a deep fondness for the AMD K6 series , they made me fall in love with their performance and unique architecture. I was born in 1994, so sadly I didn’t get to experience that golden era in real time… everything I know today comes from an endless passion for vintage hardware, fueled by curiosity and the joy of discovery.

And those CPUs you mentioned , the Cyrix chips, the K5… they’re all beautiful pieces of history, each with their own unique charm.
Your test bench with the overclocked Celeron 333 is super interesting too, I love reading about that kind of experimentation! Oh and P.S i love that SOYO BX Mobo! 😍

I’ll be more than happy to keep sharing new tests and deep dives on the channel to explore this amazing Socket 7 platform. Thanks again for sharing your experience, this is exactly the kind of spirit that makes the community so special! 🙌

I recently noticed the numerous answers, I start by saying that there are several Vogons users who love the K6, some have managed to modify the software, both to improve the support (BIOS mod of Jan), others instead to improve performance, there are also various mods. for CPU support with low VCORE, personally I started with a SOYO SY-5BT, I found the voltage resistances from 2.3V to 2.7V, this can be useful for overvolt of 2.2V CPUs, the next step will be to find the resistances for voltages from 2.1V up to 1.3-1.5V, the minimum I will find could be higher than 1.5V, I have not yet completed the experimentation, 🤞 I hope to succeed is to get at least 1.6-1.8V as a minimum.
As a source on the K6 FSB 133, I don't know how reliable it is, but it seems quite correct to me, it can be found here:

https://tweakers.net/nieuws/4964/amd-k6-2-met … 133mhz-fsb.html

Regarding the motherboards, I know that some have been put up for sale, unlike the CPUs, maybe 🤔 reading what is written in the link, it was not about the Plus versions, but the K6-2 since it writes about a 500 FSB 133.

OMG really interesting your link!
It's something very new for me, I've never come across any similar entry. I also have various various computer magazines from 1996 to 2003 but none of them talk about socket 7 to 133 MHz FSB or similar chipsets. Wow there's always something to discover!
Returning to the K6 , as you yourself said there is really a lot of interest around, and the nice thing is that after 25 years we are still here talking about it and enjoying numerous developments.
In addition to the MODs you already mentioned, let's not forget that it's only been a short time since we knew that a K6-2+ is actually convertible into a K6-III+ and I can't wait to see other discoveries in the near future!

Retroinside wrote on 2025-05-22, 13:12:

OMG really interesting your link! It's something very new for me, I've never come across any similar entry. I also have various […]
Show full quote

OMG really interesting your link!
It's something very new for me, I've never come across any similar entry. I also have various various computer magazines from 1996 to 2003 but none of them talk about socket 7 to 133 MHz FSB or similar chipsets. Wow there's always something to discover!
Returning to the K6 , as you yourself said there is really a lot of interest around, and the nice thing is that after 25 years we are still here talking about it and enjoying numerous developments.
In addition to the MODs you already mentioned, let's not forget that it's only been a short time since we knew that a K6-2+ is actually convertible into a K6-III+ and I can't wait to see other discoveries in the near future!

That's right, unfortunately many discussions are no longer present on the web, there was one in which they had given the name of those K6, but I don't remember it by heart, then being a CPU from over twenty years ago, I don't know if some specimens were actually produced, but I don't think so, because there would be some in some collection, maybe in the factory they will have done tests with FSB 133, but obviously then they chose not to use them anymore, because the Athlon mobile came out (Duron included), and they preferred to continue on that way, unfortunately there is no adapter to put a K6 on another Socket, in this regard it should be noted that VIA used the old Cyrix MII for their Cyrix III, so theoretically an S.7 could be adapted to the S.370, but I don't think it's something that can be done without a detailed knowledge of both socket