No problem.

Take a Via MPV3 or an ALI Aladdin board, and set the FSB to 100 MHz and the multiplier to 2x.

EDIT:

Look at this homepage, there is useful information.

http://www.tomshardware.com/reviews/overclock … uide,15-10.html

My AOpen AX59Pro comes to the rescue yet again. I wasn't sure if running the chip at a higher external clock would damage it in any way. Next time I pull that particular machine out, I'll give it a try.

senrew wrote:

Will any MMX chips run at 100mhz? I know people overclock up to 83 fsb on some boards but I was wondering about pushing a 166mhz with locked higher multipliers at 100x2 to get it to 200mhz instead of 66x3. Is this kind of thing doable on any of the MMX chips?

Most 200 and 233MHz MMX chips will do 250Mhz at least (FSB100). Some rare samples do 300Mhz @ 2.9v. On a good super 7 motherboard you can conceivably run a late 233Mhz MMX at 350Mhz @ 3 or 3.1v - dunno if it would be fully stable, but it should at least work in dos.

Normally I won't bother with overclocking the old hardware, but in this case, I wanted a 200mhz mmx for this build, but only had a 166 and didn't really feel like looking for yet another chip. Heh, for my purposes, speed is irrelevant as long as it does what I need.

Don't worry about damaging the cpu. Unless you increase the voltage too high.

No problem at all!! I have 8-9 of these cpus in my collection. All of them (166-200-233) do 2,5*100 in an Aladdin V board, even one of them at voltage lower than stock (2,7V), and most of them at 2,9-3 V. Only two processors do 300MHz but I had to increase the voltage very much, so I'm currently running my MMX system at 250MHz 100% stable at stock voltage 😀

250MHz was the usual sweet spot. I have one that does 300MHz on default and 315MHz at 3.1V.

Does the original rating of the chip matter when arbitrarily overclocking?

senrew wrote:

Does the original rating of the chip matter when arbitrarily overclocking?

Production date may be more important, more specifically for the later chips (due to improved yields) and at some times fast CPUs were binned for lower speeds so they wouldn't run out of slower chips which would mean people would buy AMD/Cyrix instead.

In older chips, the original rating may be of more importance. Pentium 1 MMX was a pretty solid chip though.

Be wary though that many later chips which were sold for 166MHz or 200MHz had their higher multipliers disabled.

Yeah. Checked the S-spec on the one I have here and 3.0/3.5 are disabled. That's why I wanted to ask about going 2.0 at 100fsb.

Pretty much all MMX models will run 200 to 250 mhz with 100mhz fsb with no issues at all and even some of the pre mmx models are just fine. I have had no luck going beyond 100mhz on the fsb on these procs while even some Cyrix M2s cope with 110-120 on the fsb.

senrew wrote:

Yeah. Checked the S-spec on the one I have here and 3.0/3.5 are disabled. That's why I wanted to ask about going 2.0 at 100fsb.

I've tested all my 200MHz and 166MHz chips at one time, but lost my table of test results later 😵

I do remember that sspec seemed to have nothing to do with the chip having disabled multipliers yes or no. The production date has more to do with it.
Iirc newer chips more often had some of their multipliers disabled, but in theory these newer chips should also overclock better.

Hi. I got my Asus P5A board with Pentium MMX 233MHz. I run it at 300MHz (very stable), 3x100 with 3.1V vcore. It also run at 333MHz (95x3.5) but not stable)

Debias wrote on 2017-06-11, 09:53:

Hi. I got my Asus P5A board with Pentium MMX 233MHz. I run it at 300MHz (very stable), 3x100 with 3.1V vcore. It also run at 333MHz (95x3.5) but not stable)

I recently got my hands on a P5A, and I've tried running my 233 MMX at 300MHz like you say. However I'm running into random restarts while installing or even booting Windows 98 SE.

I updated the BIOS to 1011 Beta 5 which enabled support for my larger hard drives, but in the BIOS I'm seeing a VCore 3.0 [Err] message instead of the 3.1v that I have the jumpers set to. Basically it isn't stable at all.

Edit: Did you perhaps also increase IO voltage from 3.5v to 3.6v?
Edit 2: That didn't help, it still restarted.

Any ideas?

Depends on the CPU. Some just don't overclock good. Out of 10 there could be one or two that are good.

If you want the best P-MMX overclocker, you want the Tillamook 266Mhz version:
https://www.cpu-world.com/sspec/SL/SL2Z4.html

I've tested it and overclocks to 400MHz easy.

kixs wrote on 2021-10-02, 07:23:

Depends on the CPU. Some just don't overclock good. Out of 10 there could be one or two that are good.

Thanks for the info. Though if I have to go hunt down a better CPU, I might as well just throw in the K6-2 300 that I already have and overclock that to something instead of spending more money. At least for now. 😅

Edit: Did a quick search anyways, and nobody has any for sale. Oh well...

kixs wrote:

SL2Z4

I am not yet able to use private messaging. I would be interested in the SL2Z4 that you suggested.