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P55c at Overclocked to 300mhz?

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Reply 122 of 225, by retro games 100

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I've hit the 333MHz barrier! 😀 I had to switch to the maximum allowed voltage on the mobo, and also "single voltage", for both VCore and VIO. This value was 3.5V. The system isn't very stable. Also, I had to adjust the BIOS memory settings, to make them much less aggressive.

Edit: I forgot to mention this: the mobo's FSB can be set to 95. This information can be seen here. So, we have 233 Mhz CPU with a 3.5 multi x 95 FSB = 333 MHz. (Just in case you were wondering.)

300C.jpg

Reply 123 of 225, by ux-3

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I have only one SS7 Board left in my ever declinig collection. I've once purchased 4x P1 mmx 233MHz, for minimum bid. IIRC, they would run at 300 MHz if you increased the voltage.

Regarding the K6-2: Try triggering the turbo pascal speed bug with one of them. Even at 550 MHz, my K6-2 won't trigger it. A P2 kicks it of at 266MHz. Thats efficiency!

Retro PC warning: The things you own end up owning you.

Reply 124 of 225, by bushwack

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retro games 100 wrote:

I've hit the 333MHz barrier!

Impressive! I have heard of the paint can method but never seen it in action. 🤣

I don't have a SS7 mobo worth messing with, but I have a P200mmx in my Abit 430TX regular Socket 7 able to hit 291mhz. I'm stuck with max settings of 3.5x83, but still impressive for a 1997 board.

Reply 125 of 225, by ux-3

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bushwack wrote:
retro games 100 wrote:

I've hit the 333MHz barrier!

Impressive! I have heard of the paint can method but never seen it in action. 🤣

There is also the aerosol method: Use a CPU cooler and seal the sides with some hot glue, then mount. Take a large can of compressed air and turn it upside down. Spray the (liquid if upside down) air onto the cooler. Once it has boiled of, reapply and boot. Keep reapplying while the can lasts... Avoid superconductivity at all costs or use expendable power supply. And don't try this in hawaiien shirts.

Last edited by ux-3 on 2010-10-21, 19:18. Edited 1 time in total.

Retro PC warning: The things you own end up owning you.

Reply 126 of 225, by retro games 100

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Regarding the CPU temperature, the readings were quite remarkable. At the moment, the high grade thermal paste has almost welded the heatsink to the CPU. I think that the heavy weights put on top of the heatsink has caused this to happen. Under normal processor activity load, and with no OC'ing, the BIOS tells me the temp is just 19C. With the CPU under intense strain (333MHz silly OC'ing), the BIOS told me that the temp was just 34C.

Edit: Perhaps those readings were inaccurate, because the room felt hotter and hotter! 🤣

Reply 127 of 225, by retro games 100

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bushwack wrote:

I don't have a SS7 mobo worth messing with, but I have a P200mmx in my Abit 430TX regular Socket 7 able to hit 291mhz. I'm stuck with max settings of 3.5x83, but still impressive for a 1997 board.

Very impressive. 😀
I'm about to test a regular socket 7 mobo. It's an MSI 5158 model (MS5158). The PCB says version 1, and like your Abit board, the bus speed goes up to 83. I like the connectors layout at the back. Also, it has room for either 2 72-pin DIMMS, or 3 sticks of SD-RAM.
ms5158.jpg

Reply 128 of 225, by swaaye

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You should buy yourself the big 22 gram syringe of Arctic Silver Ceramique because 1) it's excellent stuff 2) it's cheap 3) cleans up easy. It will last you forever. I know this firsthand 🤣.

Really any thermal paste is good enough for this old stuff though. The heat just isn't there like with modern hardware. But you don't want anything that dries up or separates and hardens. I've had crap like that from Radio Shack way back.

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Reply 131 of 225, by swaaye

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retro games 100 wrote:

Wow, 22 grams! I'm looking at the syringe I use: a mere 3.5g. It says: Artic Silver 5. I think it's good stuff, man. 😉

Yes AS5 is good stuff and I still have some around here. But it's only (very) slightly more thermally conductive in practice than Ceramique while being several times more money per volume. I'm not much of a believer in the "high end" pastes anymore and just want some stuff that's not garbage like the white stuff in the little packets sometimes is.

Reply 132 of 225, by Mau1wurf1977

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I admit I don't even bother with cooling paste on these old items anymore 🤣

I just mount the cooler and that't it 🤣

My website with reviews, demos, drivers, tutorials and more...
My YouTube channel

Reply 133 of 225, by ux-3

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Mau1wurf1977 wrote:

I admit I don't even bother with cooling paste on these old items anymore 🤣

I just mount the cooler and that't it 🤣

For testing in the open - sure, why waste paste?

When I test a Slot1 Mobo, I stick in an old P3-400 "handcooled" and watch if it posts.

Retro PC warning: The things you own end up owning you.

Reply 134 of 225, by swaaye

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Yeah really most of this old hardware runs so cool anyway. I usually just go with whatever's already on the heatsink if I swap stuff around. The heatspreaders that the old hardware has also makes it less important to have really good heatsink contact.

Now if we're talking a bare die Athlon, then I get the paste out for sure. You don't want to run one of those without good thermal contact or bad things will happen.

Reply 135 of 225, by Yushatak

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You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are:

1. Bus clock up to 100Mhz with a 3x multiplier.
2. Bus clock at 66Mhz with a 4.5x multiplier.

You can get a 4.5x multiplier by either buying a specially modified chip, or bridging two pins on the surface of the chip (B0 and B1 iirc) to force the multiplier. I have tried to get my chip to run at 100Mhz*4.5=450Mhz but have been unsuccessful (no POST). I currently run it at 66Mhz*4.5=300Mhz in a box with a Voodoo 2/S3 AGP combo.

Please note that I only read the first few posts, so if my information is redundant I apologize.

Reply 136 of 225, by Tetrium

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Yushatak wrote:
You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are: […]
Show full quote

You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are:

1. Bus clock up to 100Mhz with a 3x multiplier.
2. Bus clock at 66Mhz with a 4.5x multiplier.

You can get a 4.5x multiplier by either buying a specially modified chip, or bridging two pins on the surface of the chip (B0 and B1 iirc) to force the multiplier. I have tried to get my chip to run at 100Mhz*4.5=450Mhz but have been unsuccessful (no POST). I currently run it at 66Mhz*4.5=300Mhz in a box with a Voodoo 2/S3 AGP combo

think you could take a pic of your cpu and how you modded it? I haven't been able to find any info about unlocking or forcing the mmx multiplier

Reply 137 of 225, by bushwack

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Yushatak wrote:
You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are: […]
Show full quote

You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are:

1. Bus clock up to 100Mhz with a 3x multiplier.
2. Bus clock at 66Mhz with a 4.5x multiplier.

You can get a 4.5x multiplier by either buying a specially modified chip, or bridging two pins on the surface of the chip (B0 and B1 iirc) to force the multiplier. I have tried to get my chip to run at 100Mhz*4.5=450Mhz but have been unsuccessful (no POST). I currently run it at 66Mhz*4.5=300Mhz in a box with a Voodoo 2/S3 AGP combo.

Please note that I only read the first few posts, so if my information is redundant I apologize.

I tried to hard wire a higher multiplier (4x) with my Abit 430TX and aP200mmx, and it did absolutely nothing. Even tried it on multiple brand socket 7 boards. 🙁

Reply 138 of 225, by retro games 100

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Tetrium wrote:
Yushatak wrote:
You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are: […]
Show full quote

You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are:

1. Bus clock up to 100Mhz with a 3x multiplier.
2. Bus clock at 66Mhz with a 4.5x multiplier.

You can get a 4.5x multiplier by either buying a specially modified chip, or bridging two pins on the surface of the chip (B0 and B1 iirc) to force the multiplier. I have tried to get my chip to run at 100Mhz*4.5=450Mhz but have been unsuccessful (no POST). I currently run it at 66Mhz*4.5=300Mhz in a box with a Voodoo 2/S3 AGP combo

think you could take a pic of your cpu and how you modded it? I haven't been able to find any info about unlocking or forcing the mmx multiplier

Me too. The best I can find is:

If you go to this webpage: http://mysite.verizon.net/pchardwarelinks/cpuspeed.htm, and then search for: Intel Pentium w/ MMX (P55C: 5-4-3)
Then look at the comments which say: Two multiplier pins (BF0, BF1).
Then go here: http://mysite.verizon.net/pchardwarelinks/586pin.htm
Unfortunately, I can't locate pins BF0 or BF1.

Edit: BF0 and BF1 are probably mobo jumpers. Perhaps I need to locate pins B0 and B1 on the CPU. I wonder where they are? They don't seem to be labelled in the pin out diagram, from the link mentioned above.

Reply 139 of 225, by Tetrium

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retro games 100 wrote:
Me too. The best I can find is: […]
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Tetrium wrote:
Yushatak wrote:
You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are: […]
Show full quote

You have two options to get a Pentium MMX to 300Mhz - I've done it myself, actually.. anyway here they are:

1. Bus clock up to 100Mhz with a 3x multiplier.
2. Bus clock at 66Mhz with a 4.5x multiplier.

You can get a 4.5x multiplier by either buying a specially modified chip, or bridging two pins on the surface of the chip (B0 and B1 iirc) to force the multiplier. I have tried to get my chip to run at 100Mhz*4.5=450Mhz but have been unsuccessful (no POST). I currently run it at 66Mhz*4.5=300Mhz in a box with a Voodoo 2/S3 AGP combo

think you could take a pic of your cpu and how you modded it? I haven't been able to find any info about unlocking or forcing the mmx multiplier

Me too. The best I can find is:

If you go to this webpage: http://mysite.verizon.net/pchardwarelinks/cpuspeed.htm, and then search for: Intel Pentium w/ MMX (P55C: 5-4-3)
Then look at the comments which say: Two multiplier pins (BF0, BF1).
Then go here: http://mysite.verizon.net/pchardwarelinks/586pin.htm
Unfortunately, I can't locate pins BF0 or BF1.

Edit: BF0 and BF1 are probably mobo jumpers. Perhaps I need to locate pins B0 and B1 on the CPU. I wonder where they are? They don't seem to be labelled in the pin out diagram, from the link mentioned above.

Found it!

Go to this page http://mysite.verizon.net/pchardwarelinks/586pin2.htm and do a search for this: CLKMUL2
The P1 MMX is the 4th row counting from the right. It sais NC, Not Connected 🙁
Theres still a chance the official spec sheet from Intel is wrong though.

Still I'm not sure how shorting B0 and B1 ups the multi to 4.5x. I'll do some more looking around.