retro games 100 wrote:

The voltage options seem a little bit sparse: you get 2.2, 2.3, and 2.4, but the next option is 2.8, and the last is 3.2.

This is normal. Chances are good it'll have some undocumented jumper settings, or that you can puzzle them out yourself (0000, 0001, 0010, 0011 etc).
As for the differences, I don't know. Was wondering this myself. Maybe it's the chipset? Don't know, I'm just guessing here.

But most of those ATX ss7 boards should have undocumented jumper settings covering kinda every voltage in slight increments 😉

The CPU voltage is set using this -

I reckon there's some undocumented settings there. But it's risky trying them. It's not too important, I was just curious. I enjoyed "cooking" my P-233-MMX @ 3.5V last year, to achieve a speed of 315MHz. Also, I cooked a few K6-2s. When I say "cook", at the end of my experiments, the CPUs were still working.

To minimize the risks, I just put ina high voltage chip (like a pentium) and underclock the rest the lowest I can go (50Mhz fsb and 1.5x or 2x multi) and start trying out voltages in a fixed order.

Once you do it a while you start to notice that often the gaps are filled in the same way over and over.
Theres a pattern.

I think we mentioned this before, but IMO don't worry about which board and especially the amount of cache and size of cachable area.

The main thing to worry about is finding a mobile CPU (K6-2+ and K6-3+) and a board that supports that CPU. I have two boards (Aopen and Iwill which are well documented and I confirmed they support these mobile CPUs. Just dig up my old SS7 thread).

Reaseon we recommend these mobile chips is because they have onboard cache ~ 10x faster than the mainboard cache with no limitations regarding cachable size. Compared to the mainboard cache, the CPU cache is just sooo much better. All the CPUs that came after this had onboard Cache.

A 550MHz mobile K6 is pretty much as good as it gets I reckon. Boards should have a 6x Multi and FSB > 100MHz if you are into overclocking.

Here is my thread:

Super Socket 7 - VIA MVP3 or ALi Aladdin V?

Others have contributed with lot's of knowledge, so it should answer a lot of your questions.

PS: Just saw that ~ 20 people downloaded the BIOS files. That's awesome!

retro games 100 wrote:

The CPU voltage is set using this -

I reckon there's some undocumented settings there. But it's risky trying them. It's not too important, I was just curious. I enjoyed "cooking" my P-233-MMX @ 3.5V last year, to achieve a speed of 315MHz. Also, I cooked a few K6-2s. When I say "cook", at the end of my experiments, the CPUs were still working.

Personally i don't like to push that hard, but a good overclock depends on how good your mobo is.

I remember P5A has undocumented settings, allowing for very high FSB. Let me see if i still have the screenshots...

Edit: Link to my overclock in HWBOT.ORG page

This is the ASUS P5A v1.04 running a K6-2 400MHz. 😀

Although I'm more interested in older MMX chips, I think it's time to get a K6 + chip. I'm more interested in slot 1 mobos when it comes to > 300 MHz systems, but I now want to test a K6 + chip. I had a look on ebay, and saw this auction:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewIt … em=120682057487 (K6-III+ 400ATZ, 400 MHz)

The only problem is that these 400ATZ chips are 1.6V, and I think they are embedded chips. I had a look at the Epox manual, and the voltage options start at 1.8V. That won't fry these 1.6V chips, but it still sounds a bit "iffy".

Should I get one? 😐

I'm not worried about the voltage, especially considering the kind of awesome coolers you have 🤣

The K6-3+ is the best chip, as it has 256KB L2 Cache. My K6-2+ has 128KB, though it's a 550MHz model.

I don't know how much impact the extra Cache makes, I think it might be measurable, but not massive.

retro games 100 wrote:

The only problem is that these 400ATZ chips are 1.6V, and I think they are embedded chips. I had a look at the Epox manual, and the voltage options start at 1.8V. That won't fry these 1.6V chips, but it still sounds a bit "iffy".

Should I get one? 😐

I have one of these in my P5A 1.04, running at 2.0V, with a passive CPU cooler. The increased voltage is no problem at all, as the K6-III+ ATZ doesn't generate much heat.

Ah, tremendous! And that ebay seller has literally hundreds of 'em! 😁

retro games 100 wrote:

Ah, tremendous! And that ebay seller has literally hundreds of 'em! 😁

I've bought a whole bunch of K6-3+'s from this seller and all the chips are NOS and all working when I tested them 😉
I just went ahead and got a tray with 10 of these chips 😁

And don't worry about it's low voltage.
Basically it's the same chip as the 450Mhz 1.7v, the 500Mhz 1.8v etc etc.
It's just an underclocked 550 part with lowered voltage really.

OK thanks a lot people! 😀

Now I still don't know the difference between these 3 boards 🤣! 😜