kennyPENTIUMpowers wrote on 2022-10-16, 12:00:

report 2. long gaming session has resulted in a couple of crashes for this overclocked cpu.. about 45 mins into a Nascar racing […]
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report 2.
long gaming session has resulted in a couple of crashes for this overclocked cpu..
about 45 mins into a Nascar racing session it freezes or produces garbage on the screen..
this is with the standard little fan cooler on it..
so to me i consider this a fail..

of the other 2, 1 has a fan cooler and the other a solid heatsink... the fan ones have the fan stuck to them, i have no idea how to get it off and i dont really want to...
the other heatsink one is a problem because i dont remeber where i put the thermal paste..

Ok, i made a search about your P166 models and all are the ceramic one. Probably the overclock is less capable in the ceramic versione respect the plastic version. For me the P200 is one of the most fascinating CPU in a Pentium1 class. After a long search i found one at decent prize for me, unfortunately my socket5 have only 2bit for configuring cpu multiplier and i I had to modify the cpu by joining two pins. you can find a plastic "SY037" p166 for cheep on ebay.

Best to use a resistor when applying multipler mod.

This may be of use to you.

Socket 5/7/SS7 (Multiplier Mini) Tweaker (Released)

AlessandroB wrote on 2022-10-16, 13:35:

kennyPENTIUMpowers wrote on 2022-10-16, 12:00:

report 2. long gaming session has resulted in a couple of crashes for this overclocked cpu.. about 45 mins into a Nascar racing […]
Show full quote

report 2.
long gaming session has resulted in a couple of crashes for this overclocked cpu..
about 45 mins into a Nascar racing session it freezes or produces garbage on the screen..
this is with the standard little fan cooler on it..
so to me i consider this a fail..

of the other 2, 1 has a fan cooler and the other a solid heatsink... the fan ones have the fan stuck to them, i have no idea how to get it off and i dont really want to...
the other heatsink one is a problem because i dont remeber where i put the thermal paste..

Ok, i made a search about your P166 models and all are the ceramic one. Probably the overclock is less capable in the ceramic versione respect the plastic version. For me the P200 is one of the most fascinating CPU in a Pentium1 class. After a long search i found one at decent prize for me, unfortunately my socket5 have only 2bit for configuring cpu multiplier and i I had to modify the cpu by joining two pins. you can find a plastic "SY037" p166 for cheep on ebay.

Do you remember what pins you connected. I had a pre wire modified P-120 in a socket 5 motherboard in the late 90s, and get this, it was overclocked to a P200 and worked fine with heatsink and fan (I was surprised at the time but checked years later and the P120 core actually uses the newer 0.35 μm).

report 3..
i reduced the cpu down to 166 and i actually had it crash again.. this cpu is questionable... even at its default speed..

next i ran cpu 1 = su072 1996 week 34..
this one has been running well for so far at 200mhz .. no crashes .. i have been running it with the case open.. havent tried it with the case cloesed yet..

im reseaching now how to monitor the temps to see if that is having an effect or not..
also looking for a decent stress testing program that can fully put the cpu's through their paces.. prime95 seems come highly recommended

I highly doubt you are having trouble with a heatsinked pmmx at 2.8v at 166-200mhz

Perhaps your issue is elsewhere?

Pmmx doesn’t have a internal temp sensor.
Some boards had a sensor in the socket center.

Sphere478 wrote on 2022-10-18, 14:04:

I highly doubt you are having trouble with a heatsinked pmmx at 2.8v at 166-200mhz […]
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I highly doubt you are having trouble with a heatsinked pmmx at 2.8v at 166-200mhz

Perhaps your issue is elsewhere?

Pmmx doesn’t have a internal temp sensor.
Some boards had a sensor in the socket center.

yeah i doubt it too .. this is a new cpu (the first one that i tested) that i acquired last week from a recycling place .. it was in a bin ready to be thrown away .. it had a lot of bent pins that i spent several hours straightening out .. not sure how well i did but it eventually fitted into the socket..
previous to that i had a p150 chip in it that i was running at 120 then 133 and it never gave a problem.. i think the system is basically sound but i will properly stress test it.. just trying to find a version of prime95 that will run on win95 and i will also try memtest (or whatever it is called)..
oh and these arnt mmx chips just normal (3.5? single volt chips)..

Oh, my bad. 3.3v is non mmx pentium. (For socket 5/7) socket 4 is 5v

I’ve had systems with linear power supplies that crash with any chip 166mhz or faster

And forget AMD/Cyrix at any speed, put on a large heatsync with the regulators and could still fry an egg

kennyPENTIUMpowers wrote on 2022-10-18, 14:17:

it had a lot of bent pins that i spent several hours straightening out .. not sure how well i did but it eventually fitted into the socket..

If you spend hours, you've been using the wrong tool.
Get yourself a cheap mechanical pencil from the next office store and remove the graphite bar.
Fits nicely onto pins and you'll only spend 15 minutes fixing pins.

Nice trick with pencil. I use a bright light, small needle nose and a razerbalde. To line them up.

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