P2 heatsinks and fans seem to be varied a lot. I think the fanless CPUs were supposed to be installed in cases that have dedicated airflow design. E.g. the IBM 300GL flatbed has a heatsink-only P2 400MHz, but it also has a front-case standard fan that pulls air from the outside and blows it directly through the CPU heatsink long fins.

You can try going the same route if you can mount such a fan in your case with the right distance/orientation against the CPU. Otherwise yeah, you should have a fan directly on the heaksink somehow.

It might be possible to zip tie a fan to it. I did that with a Pentium II 300 processor heatsink with a 60mm Noctua fan.

Shponglefan wrote on 2026-04-10, 11:43:

It might be possible to zip tie a fan to it. I did that with a Pentium II 300 processor heatsink with a 60mm Noctua fan.

Hmm. Not a bad idea. I’d just hate for it to get so hot that they melt. 😆 But a 60mm Noctua fan… Thanks. I’ll have to look into those.

wbahnassi wrote on 2026-04-10, 07:55:

P2 heatsinks and fans seem to be varied a lot. I think the fanless CPUs were supposed to be installed in cases that have dedicated airflow design. E.g. the IBM 300GL flatbed has a heatsink-only P2 400MHz, but it also has a front-case standard fan that pulls air from the outside and blows it directly through the CPU heatsink long fins.

You can try going the same route if you can mount such a fan in your case with the right distance/orientation against the CPU. Otherwise yeah, you should have a fan directly on the heaksink somehow.

Yeah, I don’t believe my case has any room or compartment for a front fan, like my main PC has. Just the exhaust. A lot of the time, usually due to experimenting and swapping components, I have the side panel off. Also, with how much bulkier the P2 is with that heatsink, it did prove to be a tighter fit, so it’s a bit bunched up between cables etc.

DustyShinigami wrote on 2026-04-10, 12:42:

Shponglefan wrote on 2026-04-10, 11:43:

It might be possible to zip tie a fan to it. I did that with a Pentium II 300 processor heatsink with a 60mm Noctua fan.

Hmm. Not a bad idea. I’d just hate for it to get so hot that they melt. 😆 But a 60mm Noctua fan… Thanks. I’ll have to look into those.

Don't think the zipties will melt though 🤣 Especially not as long as the fan is operating. (and I think you need to pass 200 deg C for a Zip-tie to melt) and that particular heat sinks looks like it has an easy design to zip-tie to. But I would believe it's originally a heat sink made for circulation by a case fan.

H3nrik V! wrote on 2026-04-10, 12:59:

DustyShinigami wrote on 2026-04-10, 12:42:

Shponglefan wrote on 2026-04-10, 11:43:

It might be possible to zip tie a fan to it. I did that with a Pentium II 300 processor heatsink with a 60mm Noctua fan.

Hmm. Not a bad idea. I’d just hate for it to get so hot that they melt. 😆 But a 60mm Noctua fan… Thanks. I’ll have to look into those.

Don't think the zipties will melt though 🤣 Especially not as long as the fan is operating. (and I think you need to pass 200 deg C for a Zip-tie to melt) and that particular heat sinks looks like it has an easy design to zip-tie to. But I would believe it's originally a heat sink made for circulation by a case fan.

Ahh, fair enough. It's just with how hot it was to hold after taking it out... Mind you, I did attempt to overclock it a bit. I'm not sure how far it can be pushed. I read 300MHz is about the maximum, but I am curious if it can go much further before getting a BSOD or something.

But yes, I'll certainly attempt to cable tie one to it. 😀

DustyShinigami wrote on 2026-04-10, 12:42:

Hmm. Not a bad idea. I’d just hate for it to get so hot that they melt. 😆

Zip ties are typically made from nylon which has melting point of >200 degrees C. If your heatsink is getting that hot, you've got bigger problems than a melted zip tie.

Shponglefan wrote on 2026-04-10, 13:10:

DustyShinigami wrote on 2026-04-10, 12:42:

Hmm. Not a bad idea. I’d just hate for it to get so hot that they melt. 😆

Zip ties are typically made from nylon which has melting point of >200 degrees C. If your heatsink is getting that hot, you've got bigger problems than a melted zip tie.

True. 🤣

Off topic but I feel a little bit of joy every time I see these CPUs. Got a 400MHz one myself with an Intel fan

I was lucky with the heatsink design on my P2-350: it's wide and tall enough (60mm), which allowed me to install two 60mm cheap fans instead of the single 50mm fan.
I also connected fans to 5V via Molex adapter. It became significantly quieter and I don't worry about overheating.

DustyShinigami wrote on 2026-04-10, 07:42:

The attachment IMG_5466.jpeg is no longer available

Looks like a design that gets air from the side. I've seen similar on a Katmai-500 CPU I think that came from a HP or a Dell desktop.

RandomStranger wrote on 2026-04-10, 15:56:

DustyShinigami wrote on 2026-04-10, 07:42:

The attachment IMG_5466.jpeg is no longer available

Looks like a design that gets air from the side. I've seen similar on a Katmai-500 CPU I think that came from a HP or a Dell desktop.

I believe a fan can be secured to the end with 2 screws. I have so far only seen this style of HS on Dell machines.

Air will take the path of least resistance.

To work on the sides like that, it needs to either:

1) be on both sides, as 'expeller' fans, so air is taken in from the opening in the center, then pulled through the grills. Needs to be on both sides to work effectively.

2) be on one side as an 'impeller', with an air duct manifold to prevent the air just escaping out the grill after being pushed in.

I'd personally suggest a different option entirely.

3) 3D printed manifold that attaches to the heatsink at both sides with retention screws and knurled inserts. Has provision for dual noctua fans as impellers. (Similar to ott's setup, with exhaust out both sides. Fans mounted to the printed manifold. Manifold mounted on the screw provisions on either side)

Grem Five wrote on 2026-04-10, 16:46:

RandomStranger wrote on 2026-04-10, 15:56:

DustyShinigami wrote on 2026-04-10, 07:42:

The attachment IMG_5466.jpeg is no longer available

Looks like a design that gets air from the side. I've seen similar on a Katmai-500 CPU I think that came from a HP or a Dell desktop.

I believe a fan can be secured to the end with 2 screws. I have so far only seen this style of HS on Dell machines.

The attachment s-l16001.png is no longer available

Ahhh. I never noticed those notches before. But, how exactly would a fan sit on the grill and reach the hole? I'm struggling to visualise it. Especially as most fans I see in images, and much like my Pentium III, it tends to sit in the centre.

wierd_w wrote on 2026-04-10, 16:54:

Air will take the path of least resistance. […]
Show full quote

Air will take the path of least resistance.

To work on the sides like that, it needs to either:

1) be on both sides, as 'expeller' fans, so air is taken in from the opening in the center, then pulled through the grills. Needs to be on both sides to work effectively.

2) be on one side as an 'impeller', with an air duct manifold to prevent the air just escaping out the grill after being pushed in.

I'd personally suggest a different option entirely.

3) 3D printed manifold that attaches to the heatsink at both sides with retention screws and knurled inserts. Has provision for dual noctua fans as impellers. (Similar to ott's setup, with exhaust out both sides. Fans mounted to the printed manifold. Manifold mounted on the screw provisions on either side)

Ahh, so, in the case of this heatsink, the fans need to be attached on the sides...?

The original design likely used a big black plastic ducting cowl that uses the PSU's expelled air as the airsource, with the cowl connected at the sides.

Since using psu air that way is garbage, i'd rather DIY a proper fanmount.

The mounting locations are on the sides.

DustyShinigami wrote on 2026-04-10, 17:21:

Ahhh. I never noticed those notches before. But, how exactly would a fan sit on the grill and reach the hole? I'm struggling to visualise it. Especially as most fans I see in images, and much like my Pentium III, it tends to sit in the centre.

I had to go dig up mine.

Grem Five wrote on 2026-04-10, 17:52:

I had to go dig up mine. […]
Show full quote

DustyShinigami wrote on 2026-04-10, 17:21:

Ahhh. I never noticed those notches before. But, how exactly would a fan sit on the grill and reach the hole? I'm struggling to visualise it. Especially as most fans I see in images, and much like my Pentium III, it tends to sit in the centre.

I had to go dig up mine.

The attachment 20260410_124443.jpg is no longer available

The attachment 20260410_124401.jpg is no longer available

Great. Thanks for doing that. 😀 Can't say I've ever seen them set up on the sides before. I certainly learn something new every day. 😁

wierd_w wrote on 2026-04-10, 17:25:

The original design likely used a big black plastic ducting cowl that uses the PSU's expelled air as the airsource, with the cowl connected at the sides.

Since using psu air that way is garbage, i'd rather DIY a proper fanmount.

The mounting locations are on the sides.

The ones I have seen draw air through the HS by way of a shroud and rear case fan.