The real situation is that it dosnt really matter, they all can do ~600 Mhz at 1.9 - 2.2 volts but not much more.
The max released speed is 575 Mhz for K6-2+ and 550 Mhz för K6-3+ just as you wrote.

Im sure there are lots of fakes as they all clock about the same but it dosnt really matter if you run a K6-3+ 400 1.6v at 550 MHz 2.0V or if you run a real K6-3+ 550 at 550 MHz 2.0V

For the Vanilla K6-3 the max released speed is 450 MHz and they do not clock higher than 500 - 525 MHz at any voltage.
The Vanilla K6-2 was released in speeds up to 575 MHz but speeds over 500 MHz did not really improve the performance because of the FSB bottleneck.

Thank you, I really heard every kind of stories about it! I didn't find the 575Mhz K6-2 at that time so I can imagine the officially labeled one was rare. I hope to fine the 550 K63+, quiet interesting processor. I tested the K62+ 533 some time ago and it was a nice processor quiet fast and cool.
Actually I am testing the K63-400 / 2.4v. Sure it's runs hot but it's certainly a good processor even if I can't really say if faster of the K62-500. It feels quiet the same at the original freq.

The guy on ebay who has a truckload of them recently raised his prices to crazy stupid levels. He was having trouble selling them at $25, then all of a sudden he raises the price to almost $150. I don't know what his thought process is that justifies doing that. He's only going to kill whatever sales he was getting at $25. About 2 weeks before he raised his prices I managed to find a K6-2+ 550 and a K6-2+ 570 from other sellers for less than even the $25 that he was charging originally. I also managed to pick up a K6-III+ 450 in the the same price range as the other two and IIRC, they will all hit 600mhz with the right motherboard.

Err, the only correction is - Amd K6-2-570 (6x95) MHz, not 575...

Gamecollector wrote:

Err, the only correction is - Amd K6-2-570 (6x95) MHz, not 575...

Yea that is correct, many did run them at 5.5x105 = 577 though as the 95 FSB diddnt make much sense.

Got here k6/2+ 570ACZ, 6*95, but now 5,5*100 with ga-5ax F4

I have a K6-2+ system with a 570 MHz CPU running at 6x100 MHz.
On Asus P5A with Quadro2 Pro, V2 SLI, Adaptec 2940UW, Quantum Atlas 10K, Terratec Base1+Radio+WT64.
Benchmark results and pictures here: ftp://78.46.141.148/pictures/bench_results/K6-2p_600MHz/

Well, AMD isn't Cyrix (40 and 55 MHz bus speeds, yeah...) but still have several innovations in the FSB speed area... 95 MHZ is one of them.
IIRC there were 96.(296) MHz (4.5x=433) and 96.(96) MHz (5.5x=533) too.

Have anyone here a real official K6-3+ 550?

386SX wrote:

Have anyone here a real official K6-3+ 550?

No...

Only got a lot of those 400s 😁

I just checked ebay, almost €20 each? wow

But oh well, at least he sold tons of his chips for good prices, including to many members here.

sliderider wrote:

The guy on ebay who has a truckload of them recently raised his prices to crazy stupid levels. He was having trouble selling them at $25, then all of a sudden he raises the price to almost $150. I don't know what his thought process is that justifies doing that. He's only going to kill whatever sales he was getting at $25. About 2 weeks before he raised his prices I managed to find a K6-2+ 550 and a K6-2+ 570 from other sellers for less than even the $25 that he was charging originally. I also managed to pick up a K6-III+ 450 in the the same price range as the other two and IIRC, they will all hit 600mhz with the right motherboard.

Here's a theory: Someone replacing industrial components or business systems that needs those specific parts bought a few and he jacked up the price since he knows a business will pay out the ass.

Generally when your stock is running low you jack up the rates for the last few and sit on them.

Skyscraper wrote:

The real situation is that it dosnt really matter, they all can do ~600 Mhz at 1.9 - 2.2 volts but not much more.

I know this is an old post, but I feel I should clarify that this statement isn't 100% true. Most K6-2+ and K6-III+ chips will indeed hit 600MHz with relative ease, especially K6-2+ CPUs. However, there's still a chance you won't be able to reach 600MHz. I have two such chips that just won't go above 550-575MHz and I'm still looking for one that will hit 600MHz 😜.

Unknown_K wrote:

Generally when your stock is running low you jack up the rates for the last few and sit on them.

This is a very good observation I think, personally I would've done the same.

F2bnp wrote:

Skyscraper wrote:

The real situation is that it dosnt really matter, they all can do ~600 Mhz at 1.9 - 2.2 volts but not much more.

I know this is an old post, but I feel I should clarify that this statement isn't 100% true. Most K6-2+ and K6-III+ chips will indeed hit 600MHz with relative ease, especially K6-2+ CPUs. However, there's still a chance you won't be able to reach 600MHz. I have two such chips that just won't go above 550-575MHz and I'm still looking for one that will hit 600MHz 😜.

Just wondering, which chips have failed to reach 600MHz for you and how many have you tried so far?
Tbh, I wouldn't have been bothered really that much if 550MHz does run stable 😊

F2bnp wrote:

Skyscraper wrote:

The real situation is that it dosnt really matter, they all can do ~600 Mhz at 1.9 - 2.2 volts but not much more.

I know this is an old post, but I feel I should clarify that this statement isn't 100% true. Most K6-2+ and K6-III+ chips will indeed hit 600MHz with relative ease, especially K6-2+ CPUs. However, there's still a chance you won't be able to reach 600MHz. I have two such chips that just won't go above 550-575MHz and I'm still looking for one that will hit 600MHz 😜.

575 MHz is ~600 MHz in my book! 😉

Tetrium wrote:

Just wondering, which chips have failed to reach 600MHz for you and how many have you tried so far?
Tbh, I wouldn't have been bothered really that much if 550MHz does run stable 😊

I've tried a couple of K6-III+ 400ATZ and both max at 1.9V 550MHz. My OCD is strong though, I really need those 50MHz to round up that number and achieve the insane performance of... a Pentium II 350 🤣 .

Skyscraper wrote:

575 MHz is ~600 MHz in my book! 😉

And you'd be totally right, but I'd really love to hit 600 with one chip. I love these little buggers!

I understand you. It's like with my 286 board. It runs stable at 24MHz but freezes soon at 25MHz 🙁

I do have only one of K6-III+ 400ATZ but didn't yet tried overclocking it. But I hope it does 600MHZ 😉

So it seems that the 550Mhz that was theoretically released is quiet rare. I only have the one I'm writing on, a K6-2+ 500 and running good but if I want to make this config running at max/time-correct/not-overclocked, I hope to find the better one (k62+-570 or k6/3+550) and also a better mainboard... (not mvp3).

There is a reason AMD stopped at ~ 570 MHz. Just my 2c 😀