I have a Deskpro with a Pentium 166MMX that has a huge heatsink but no fan. So if your heatsink is good and you have enough airflow you’re probably good to go.

Kouwes wrote on 2024-06-15, 09:55:

I have a Deskpro with a Pentium 166MMX that has a huge heatsink but no fan. So if your heatsink is good and you have enough airflow you’re probably good to go.

A Pentium P55C 166MMX runs cooler than a P5 P60 (13W vs 15W), so that's not necessarily conclusive.

Big bit of info missing here: what heatsink? And how is the airflow around it?

My first 'own' PC was a P60 with a miniscule (<1cm high) heatsink that absolutely needed the noisy 40mm fan on it to keep the CPU from melting, particularly in my cramped tiny minitower with nothing even resembling cable management. Most passive heatsinks used in Compaq systems for P166MMX were oversized, overhanging the socket on at least one end, and having quite tall (>1.5cm) fins/spines, as well as an integrated airflow design that made sure that there was a constant stream of air over the heatsink.

If the P60 has a setup similar to that, it can easily be cooled passively (and that 2W difference in TDP won't matter too much), if however it resembles my old system, it most definitely cannot.

Until recently over het a Compaq Deskpro 2000 with P200 cpu that was kept cool the same way.

With open case it stayed pretty cool but with closed case temps could get to levels I'm not comfortable with. Little too hot to touch for more than a few secs.

So the fan in front of the case does the job and the case itself is the limiting factor.

yeah my p-60 from a Compaq with glued on passive HS, same size as the cpu but is 1" or 2.5cm total height. sticker says 616971-001 60mhz. case had a fan blowing over it iirc

My P60 with its chunky big stock heatsink gets alarmingly hot without airflow. But with just a fan nearby to move some air it is enough to keep it cool.

P60s ran very hot. They run at 5V.

IMHO P60 should not run with only a "true" passive heatsink i.e. zero air flow and cooled only by the ambient room temperature that most people are comfortable with (20-25°C); a fan is needed either directly atop the heatsink or installed on the chassis near it to create sufficient air flow.

My 29-years-old Dell P120c has no fan on the heatsink, but a chassis fan is located near the bottom of the front panel, blowing air directly to the heatsink. It runs well even after I've overclocked the CPU from 120 to 133 simply by changing the FSB jumper from 60 to 66. This would increase its theoretical TDP from 12.8W to 14.2W, almost on par with a P60 (14.6W).

As other have said a fan blowing air over the area or heatsink directly would be the best setup, I have little doubt the P60 could run without direct air cooling if the heatsink was a beefy one and the case was well ventilated and in a temperature controlled environment but such a setup is not likely at home.

I have a giant Deskpro heatsink on eBay right now. It's 9.7cm x 6.5cm (3.8" x 2.5"). ~1inch tall.

A fan blowing from far away is all it needs.

Even the P2 350 in Compaq Deskpro EN SFF is cooled by aluminium passive heatsink, the necessary airflow provides 80mm fan on the PSU. AFAIK same cooling system is used even for PIII in this model series, but my PIII 550 has small 40mm fan right on heatsink.

I don't think people realize a P60 runs hotter than most of these chips that are being used as examples for passive cooling.

MikeSG wrote on 2024-06-16, 06:53:

I have a giant Deskpro heatsink on eBay right now. It's 9.7cm x 6.5cm (3.8" x 2.5"). ~1inch tall.

A fan blowing from far away is all it needs.

This is the kind of sink used on the Deskpro 2000 😀
Indeed it has enough mass to transport heat and enough surface to dispatch it again, while the case fan blows gently right over it providing all the air flow it needs.

It's used on the P200 with about similar tdp so with the case fan it should be ok 😀

Case fan *and* good cable management for unobstructed airflow *and* that airflow itself (i.e. enough outtake area - or additional fan - to get rid of the heat in the air that the front fan blows over the heatsink). Those Compaq systems were brilliant designs in terms of airflow and vastly superior to a random AT system with a front case fan somewhere near the CPU.

I have a Packard Bell P60 system with a huge heatsink and case fan blowing air over that heat sink. Back in the day those systems would have the fan fail from dust and the CPU would kill itself.

i have a Desktop IBM P60 with a big (3cm at leat) passive eathsink plus a front fan that cool the are (is half directly to the cpu). If ibm sold a system like that i think that can work passive with a ragionable airflow near

AlessandroB wrote on 2024-06-16, 20:49:

i have a Desktop IBM P60 with a big (3cm at leat) passive eathsink plus a front fan that cool the are (is half directly to the cpu). If ibm sold a system like that i think that can work passive with a ragionable airflow near

Airflow doesn't only need to be good near the heatsink - which transfers heat from the sink to the air, it also needs to be good elsewhere in the case to get rid of that hot air.

Don't get me wrong, I'm a huge fan of passive cooling, but it's more than just 'make sure there's a case fan blowing over the heatsink'. In fact outtake fans are more important than intake fans- if you have a good outtake fan high up at the back of the case, it will pull hot air out. If there's an opening in the front of the case near the CPU, it will draw in cool air into the case and over the CPU, which will work a lot better than having a fan nearby blowing air onto it, but nothing behind that.

dionb wrote on 2024-06-16, 21:56:

Airflow doesn't only need to be good near the heatsink - which transfers heat from the sink to the air, it also needs to be good elsewhere in the case to get rid of that hot air.

Ditto, and that was why the early design of GeForce FX 5800 Ultra got its notoriety: the hot air exhaust was located right above the cool air intake, resulting a portion of hot exhaust got sucked back into that fluorescent-green air duct.

dionb wrote on 2024-06-16, 21:56:

Don't get me wrong, I'm a huge fan of passive cooling, but it's more than just 'make sure there's a case fan blowing over the heatsink'. In fact outtake fans are more important than intake fans- if you have a good outtake fan high up at the back of the case, it will pull hot air out. If there's an opening in the front of the case near the CPU, it will draw in cool air into the case and over the CPU, which will work a lot better than having a fan nearby blowing air onto it, but nothing behind that.

Most modern mid-range or better ATX PSU have their own fans to cool themselves and create at least some degree of constant air flow within chassis, especially when installed on the upper end of a typical old-school ATX chassis (personally I'm not fond of bottom-mounted PSU design of most modern chassis). Most AT PSU and low-end ATX PSU have no fan of their own, however.

The P60 in my Proliant 1000 has only a passive heatsink too, but its supported by a big fan next to it.
Even the P60 Boards for the 4 CPU Proliant 2000/4000 have only passive heatsinks.

NightShadowPT wrote on 2024-06-15, 09:49:

Hi, […]
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Hi,

I have a Pentium 60 on the way to upgrade my Compaq Deskpro M and would like to know if the Pentium 60 requires a fan, or if it will work only with the Heatsink?

Note: I have a large fan that is circulating air through the area where the processor will be, but I'm looking to understand if they also need a CPU fan, or if this will be enough?

Thanks

Guessing you bought the one on ebay that the dude was asking $275 for last week? May I ask what offer he accepted?