Baoran wrote:

Does that also apply to klamath version of pentium 2? Wouldn't that mean also that a quieter 50mm would be enough?
It is really too bad that there is no way to monitor the cpu temperature with this cpu. Like there is no way of knowing if the old thermal paste is going bad after almost 20 years.

yeah pretty much any pentium 2 under 350mhz has the option to be fanless if the heatsink is big enough , usually a case fan with a vent will blow on it.

but yes a 50mm will work , or you can ziptie any fan at all onto it. so long as theres some air flow it'll be fine.

and yes , the thermal paste is bad , no need to check , it's definitely bad. it's the cheap white stuff. However , it doesn't really need to be good at all. keeping in mind a pentium 1 233mhz would routinely be installed without any thermal paste at all.

You would think it would be other way around since klamath 300Mhz has the highest tdp of all pentium 2 processors and the tdp is twice of those newer high clockspeed ones.

emosun wrote:

yeah pretty much any pentium 2 under 350mhz has the option to be fanless if the heatsink is big enough , usually a case fan with […]
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Baoran wrote:

Does that also apply to klamath version of pentium 2? Wouldn't that mean also that a quieter 50mm would be enough?
It is really too bad that there is no way to monitor the cpu temperature with this cpu. Like there is no way of knowing if the old thermal paste is going bad after almost 20 years.

yeah pretty much any pentium 2 under 350mhz has the option to be fanless if the heatsink is big enough , usually a case fan with a vent will blow on it.

but yes a 50mm will work , or you can ziptie any fan at all onto it. so long as theres some air flow it'll be fine.

and yes , the thermal paste is bad , no need to check , it's definitely bad. it's the cheap white stuff. However , it doesn't really need to be good at all. keeping in mind a pentium 1 233mhz would routinely be installed without any thermal paste at all.

Personally I wouldn't run that CPU with that heatsink without any HSF. The fins on the HS look quite inadequate for passive cooling and the original HSF probably had a very high RPM for a reason.

You can see the thermal specifications on this page. Do a CTRL+F for "Klamath" to get to the right part. Even the slowest Klamath seems to run hotter than the fastest Deschutes and 43W max is as much as an early Thunderbird.

What would you think about if I would put that Gelid Solutions Silent 5 that someone recommended there and I would change the multiplier to 3x?

I used rubber bands to secure a 80 mm fan to a Klamath 300. They do pull 20 W more under load than Deschutes 333. Cooler should be easy to remove, it's either screwed on or has hooks going through.

Zip ties FTW!

Is there a video on how to remove the SECC1 P2 heatsink/fan? I have a P2-350 with Intel stock cooler, and can't seem to figure out how to change it.

It's hard to make accurate comparisons because airflow varies depending on the resistance that the fan is pushing against. Fan datasheets will show a graph of pressure vs airflow. Different fan designs will have a different balance between those 2 things. But you're unlikely to find detailed info like that for both fans.
Personally I just assume that if 2 fans appear to be similar in design, then if their power ratings are similar then performance (and noise) are probably also similar. That's not very rigorous but I think it's realistic. I'm skeptical of quieter fans without tradeoffs, unless you change the physical dimensions or one of them is worn out.

Does your board have any way to undervolt the CPU a bit? Power consumption==heat and this varies with the square of voltage, so undervolting is very effective at reducing the heat. That can make it easy to use a much quieter fan. Underclocking helps a bit, but the main value is that a slower clock allows more undervolting.
Another way to look at it is that a somewhat higher CPU temperature might still be okay. The fan choice probably isn't really that critical.
My main concern with heat would really be how it affects nearby motherboard components. The CPUs are pretty robust and cheap.

dexvx wrote:

Is there a video on how to remove the SECC1 P2 heatsink/fan? I have a P2-350 with Intel stock cooler, and can't seem to figure out how to change it.

Untill now I had 4 different P2 CPU and all had a different mounting system, making a already annoying job even more so...

Today I got another pentium 2 cpu for free. It doesn't have any fan at all, so I am bit worried about putting it in the computer that doesn't have case fans. At least the heat sink in this seems to be easy to remove.

Baoran wrote:

Today I got another pentium 2 cpu for free. It doesn't have any fan at all, so I am bit worried about putting it in the computer that doesn't have case fans. At least the heat sink in this seems to be easy to remove.

20170405_121703_001.jpg

That's much better!

These heatsinks were often used by OEMs and I've got several that are similar to yours.
You should be able to mount a fan onto that. What CPU is it exactly? nvm, it's a P2-450.

Is the side with all the little fins all level? Some were uneven and in that case you'll have to do a little bit more fiddling around. But a fan on top of that should work.

The pins are at same level, but there are no holes for any screws for the fan. There is just those 4 holes where the pins go through the board to the metal part that you can see in the first picture of the cpu.

Baoran wrote:

The pins are at same level, but there are no holes for any screws for the fan. There is just those 4 holes where the pins go through the board to the metal part that you can see in the first picture of the cpu.

20170405_171806.jpg

Many of these passive Slot 1 heatsinks were never meant to have a fan mounted on them.
I'd ignore the holes in the CPU and use something like clueless1 has done. You'll just have to get a little bit creative now 😜

Baoran wrote:

Does that also apply to klamath version of pentium 2? Wouldn't that mean also that a quieter 50mm would be enough?
It is really too bad that there is no way to monitor the cpu temperature with this cpu. Like there is no way of knowing if the old thermal paste is going bad after almost 20 years

I suggest replacing it to increase thermal conductivity, most thermal paste tends to harden over the years. The first thing I do when recieving hardware is replace thermal paste.

One fun thing I have done with passive heatsinks like that is to identify where you want the fan, mark off where the fan screws would go, and using a pair of pliers to push the aluminum fins together, then screw the fan in. Seems to work pretty well and good threaded screws will score the aluminum and make for a fairly solid mounting point.

I think a 80mm fan and 2 zip ties going underneath the heatsink where the heatsink is higher and through the screw holes of the fan might actually work. If I will be find thin enough zip tie to go through the screw holes and still long enough to go all around the heatsink.