I recently got a old Pentium MMX 200Mhz, it doesn't get above Ambent with its cooler, I want to see if I can overclock it, Would it be possible to get another 100Mhz out of it?

Please list the entire system specs.
One important question right off the top, is your RAM up to the task?

Those old 200s used to do 225, 233, and sometimes 250, IIRC. I think setting the FSB to 83 mhz was the sweet spot, though my memory fades on this. Of course this was typically done with jumpers on the motherboard back then. You need to have a MOBO that had these jumpers. That was about it. You'll need to see what multiplier the chip is set to and then set your FSB accordingly. IIRC 66 mhz RAM was USUALLY up to the task of running at least 75 or 83, maybe even 100.

ETA MOST Intel chips were multiplier locked (at least the higher multies were) by the time of the 200 MMX. But maybe not all of them. It is worth playing with the multi jumpers just to see.


Many MOBOs back then had these settings actually printed on the circuit board right near the jumper panel. I think the default FSB for the 200 was 66 mhz which would make the multi 3.0. 75 mhz ought to be very doable. Then try 83 if your board has that option.

You could also tweak the cpu voltage with jumpers, but I never tried that myslef.

Also, adding a little HS grease was advisable. I don't think those old sinks came with any.

I can't find the Motherboard Model, but it has Two ISA slots, Three PCI slots, and one AGP 1 or 2x slot, the RAM is some SDRAM, 164Mbs I think, Not sure of speed though and its got a VIA chipset with the jumper OCing, so what should I try first?

[url=http://en.wikipedia.org/wiki/Image55c-233.jpg]Here is what it Looks like.[/url]

So you found the bus speed jumpers on the MOBO?

If it is currently set to 66 I would simply raise it to 75. Then (to be safe with your HD data), before you attempt to boot I would unplug the HD and I would boot off a 'memtest86' floppy http://www.memtest.org/download/1. [...] floppy.zip
and see if it gets through a half hour or so without error. If so I would then try boot up Windows and see if you seem to be stable.

Then I would try 83 mhz and repeat the same steps. Unfortunately the 83 mhz setting was sometimes omited from the jumper settings label on the mobo. You had to look it up eleswhere. Since this is a VIA chipset things may be different for you. Not sure if I ever tried OC a VIA. You could also use process of elimination by tryin g the combos not listed. This could of course be risky but I did it a few times with good luck.

The PCI bus is going to be running at 83 too because in those days the PCI bus ran at FSB speed. oops, actually I think it ran at HALF of FSB speed, but the principle is the same. This is why you want to be careful with the HD being hooked up. You could get some data corruption if you push FSB too far.

I used to run at 83 mhz routinely in the old days so it should work, as far as the RAM and HD are concerned, can the CPU run at 250 is another question. Some thermal grease is a big help. Those old systems came without any pre-applied IIRC.

I am working off 10 year memories here, so you may wish to dbl check my advice.