I don't think fun is required 😜
But I think having a fan can be a good idea (heatsink too).

So there is no risk of overheating?

Cpu will work without cooler but as far as i know , high temperatures are not good for semiconductors, so the cooler is just good practise

Certianly helps but DX2 66s can run fine with just a fan blowing cool air on them

if it is a 5V model I would definitely go with a heatsink, they get really hot, even with one. 3.3V models should be able to get away without, but I would try to find one anyway.

I'm having problems with a dx2-66 having a quite unstable behavior without any heatsink or fan attached. My previous dx33 would work just fine without them. I just ordered one to try it out and see if it solves these issues or is just a faulty CPU.

DX2-66 (3.3V) will work fine without a heatsink, it's really just the longevity that comes into question -- no different than running a modern chip at temperatures so high it's forced to throttle. To avoid electron migration conversations it's best to just remember the phrase "Heat Kills."

In it's time ( < 1995 ) it was generally suggested to start using a heatsink on DX2 chips or higher. Our DX2-66 system came with a fanless heatsink and lasted many years. 5v chips are known for getting hot, I would have a heatsink + fan on them without question.

I run a heatsink + fan combo I grabbed off of ebay for like $10 (overpriced), but I'd rather baby the CPU and have it last longer over having to buy replacements. I threw in an intake fan to put a bit of air over the board and cards as well because why not..

Based on what you say, I guess my dx2 is faulty probably bc it was operated without any heatsinks by its previous owner. Damn 🙁 I'm back to 33Mhz. I'll try the heatsink when it arrives as it's already on its way. Thanks!

I got some 40x40x15mm heatsinks from an eBay HK seller and some AKASA AK-TT12-80 THERMAL ADHESIVE TAPE pads so I can stick the heatsinks to all 386/486 cpus I have. 40x40x10mm fans on top when needed, there is no point nowdays not to add at least a heatsink IMHO
I even stick small 20x20x8mm heatskinks to 386sx cpus 🤣

Any cheap Chinese chipset cooler with a thermal adhesive pad/sticker on the back will work just fine, you can also install a front mounted case fan near by if that is an option. Some of those 80mhz DX2s do run on the hot side but cooling a common 66 is easy.

I just slap a heatsink with fan, on every 486 from and including dx33. Especially if there is components right next to the cpu socket. Better safe than sorry. And why not? Active cooling can still be found at a reasonable price on eBay from time to time.

I took some time to find coolers in ebay that would clamp to the cpu (around 10€ shipped, including fan and heatsink). This thermal adhesive solution sounds great in theory but I have my doubts it will perform adequately in practice. What's been your expirience with them so far? Is there an easy way to measure temp in this old computers?

jsp wrote:

Based on what you say, I guess my dx2 is faulty probably bc it was operated without any heatsinks by its previous owner. Damn 🙁 I'm back to 33Mhz. I'll try the heatsink when it arrives as it's already on its way. Thanks!

I forgot to report back from my experiment. My Dx2-66 is operating without issues since I attached a heatsink (no fan), which means it's stable if the temperature is kept within a reasonable range. That's great news, I'm now looking at potential fans that I could install on top to extend the life of this nice cpu as much as possible. I want something extra-silent, probably one of this noctua fans. Attaching it to the heatsink will be my next challenge!

^You could also just drive a common 40 or 50mm fan with 5V. It would likely be quiet enough + still provide enough cooling.

SW-SSG wrote:

^You could also just drive a common 40 or 50mm fan with 5V. It would likely be quiet enough + still provide enough cooling.

Do you mean 5v as opposed to 12v to reduce RPM? Neat idea, I'll try that and report back!