The 486 DX33 don't need a cooler, but it's still a great idea to cool them down a little bit more to make them last longer. The 486DX2 66 and faster otherwise are meant to be used with a heatsink.

passive on low-end and active on high-end hardware, but i don't think one can go without; there was a voltage change in that era too, maybe You're just too generous?

I used my Intel 486DX2/66 without a heatsink for a couple of weeks without any problems. Then when I was able to source one, I put it on just to be safe. I think on the cpus that required one, they printed it on the cpu. But yeah, why not put one?

I don't actually have anything that I can attach to the cpu. Only thing holding the heatsink to the cpu was bit of thermal paste during my testing.

Fans from the period often had plastic clips to go under the CPU package and hold both the fan and heatsink in place. 486 cpus were fairly cool running, so even the hottest running versions didn't really need perfect contact.

Would something like this work?
http://www.ebay.com/itm/NEW-AAVID-Ultra-Quite … =item3ae4100da6

I don't know if my cpu is socket 1, 2 or 3 though. Is there some other way to recognize which socket it is other than taking it out and counting the pins?

Baoran wrote:

Would something like this work?
http://www.ebay.com/itm/NEW-AAVID-Ultra-Quite … =item3ae4100da6

I don't know if my cpu is socket 1, 2 or 3 though. Is there some other way to recognize which socket it is other than taking it out and counting the pins?

Yep, that'll do the trick! It clips to the cpu, not the socket, so no need to worry which socket. I know around socket 5 it was printed on the socket itself:
https://en.wikipedia.org/wiki/Socket_5
and it seems like I've seen "Socket 3" printed on sockets, but not sure about earlier. Here's a couple of pages that might help:
https://www.computerhope.com/jargon/s/socket1.htm
https://www.computerhope.com/jargon/s/socket2.htm
https://www.computerhope.com/jargon/s/socket3.htm

clueless1 wrote:

Yep, that'll do the trick! It clips to the cpu, not the socket, so no need to worry which socket. I know around socket 5 it was printed on the socket itself:

That's exactly what you want. Actually, it clips under the CPU package, above the socket. There's a picture in the listing.

My Am486-DX4-100, which is running @ 120mhz is using a cooler, but any 486 66mhz and slower does not need any cooling. If you are concerned about it, feel free to blow air from a case fan onto it, but it's not needed.

A DX-33 does not need any sort of cooling, and can survive to around 100c +/- 10c, with cooler temps resulting in longer life span and less power draw. If you were to touch a 100c CPU, you would burn yourself almost instantly. So if you don't get a burn instantly, your CPU is about fine.

You should have at least a passive Cooler on any 486 up to 75Mhz for long lifetime.

I agree on using at least a passive cooler on older 486 CPU's.

A 486DX-33 doesn't require a heatsink and/or a fan but, as already stated, having one will let it run cooler (I've done it with my 486DX-33).
I would not recommend running a 486DX2-66 without at least a heatsink or some fan blowing over it (preferably the former, with a fan attached, to ensure adequate cooling).

The retail overdrive DX2-66 came only with a small heatsink and no fan, and even the overdrive DX4-100 also used heatsink only, although a larger one. Maybe Intel chose more heat-tolerant chips for the overdrives, but they seem to be fine without a fan.

More cooling will never cause problems, so if you're not sure, it's safe to throw a fan on.

TheMobRules wrote:

The retail overdrive DX2-66 came only with a small heatsink and no fan, and even the overdrive DX4-100 also used heatsink only, although a larger one. Maybe Intel chose more heat-tolerant chips for the overdrives, but they seem to be fine without a fan.

I never understood what was the point of that chip. I do own one, but what's the difference between a normal DX2-66 ? I've never heared of any motherboard made for 486DX-33 that couldn't run a 486DX2-66. Was that just marketing ?

Deksor wrote:

TheMobRules wrote:

The retail overdrive DX2-66 came only with a small heatsink and no fan, and even the overdrive DX4-100 also used heatsink only, although a larger one. Maybe Intel chose more heat-tolerant chips for the overdrives, but they seem to be fine without a fan.

I never understood what was the point of that chip. I do own one, but what's the difference between a normal DX2-66 ? I've never heared of any motherboard made for 486DX-33 that couldn't run a 486DX2-66. Was that just marketing ?

A good point.

The 486DX2-66 started out as a 5V chip. So, regardless on whether you have the standard CPU or the Overdrive CPU, it should run in most older 486 motherboards without any problems. However, I think that the Overdrive CPU's had L1 write back cache where the standard ones (initially) had L1 write through cache.
The only reason I can think of for the 486DX2-66 Overdrive was as an upgrade path for older motherboards where the CPU was surface mounted (provided the motherboard had an upgrade socket).
However, the 486DX4-100 Overdrive is a different story, since the standard CPU was a 3.3V chip, but the Overdrive had a voltage regulator (specifically catering for older motherboards that didn't have a voltage regulator and therefore only supported the older 5V CPU's).
Not sure how the BIOSes on those older motherboards would "read" an Intel 486DX4-100 Overdrive CPU.

My DX2-66 is heatsink only, runs quite hot but it's never had problems.

Just slap on a passive cooler and install a case fan then you are set, on higher clocking chips active cooling is nice as some get pretty hot though still very stable. I use active cooling on the more rare procs.