Heatsink?

[mehguy]

Why do CPU's of past don't need any kind of heatsink? Around the pentium era, CPU's started to become required. Why is that? Why did so CPU's before that time do fine without them?

 

EDIT: Woops, this was meant for the classic computing forum, could a mod move it?

Edited August 5, 2016 by mehguy

[Video]

Basically power consumption wasn't sufficient for the die size till then. Newer processors generated enough heat the chip could physically melt from the heat.

 

Interestingly one common way to overclock early processors was to use a Heatsink or fan or other means of cooling to run more power through them. But for the average Joe they weren't needed.

 

Some early chips could take enough heat to melt solder joints and physically unplug themselves. I seem to recall tempest having this issue in early models. Some early computers could unseat their chips too. I seem to recall some apple computers where their fix was to physically drop the machine to reseat their chips. No fooling that was a suggestion from apple themselves. I always thought that was dumbassie but what do I know?

Edited August 5, 2016 by Video

[CatPix]

I recal reading that the consumption of the Intel 8080 was around 0.1watts, today it's more 100 watts in average.

[Osgeld]

yes its power consumption and density

 

intel 8086 has 29,000 transistors (according to wikipedia) and a pentium non mmx has 3.1 million on a wafer not that much larger

more stuff means more power which means more heat, more stuff packed together tighter means its harder to get the heat out (but you cant space it out or else it starts using even more power while also getting slower)

Edited August 5, 2016 by Osgeld

[CatPix]

Note that some CPU of the time needed them already, the Bally Astrocade boards need at least one heatsink, and when you have one running, you feel that adding a heatsink on the other chips can't hurt.

Some models of Intellivision are prone to overheating too, and adding a heatsink to the CP1610 can't hurt either.

[Nebulon]

There used to be a good video out there on the web of a dude pulling the heat sink off of an early 2000s AMD chip while using a laser temperature sensor. The temperature skyrocketed and then the CPU lit on fire.

[Professor Gull]

Coming from working in the industry that made machine to make microchips the number of transistors on the chips just grew as the processes got more miniaturized.That then allowed for more chip connections which then required more voltage and that created more heat. Its funny to even see RAM chips now needing heat sinks as well. But then one might wonder why cell phone chips tend not to need such buffed heat sinks. Pc chips are silicon based and the mobile chips were done on gallium arsenide which allows for more heat to passed through the chips without worrying about over heating per sey.

 

But that was like 10 plus years ago so I would imagine the same applies now especially with more voltage being needed as well.

[fiddlepaddle]

Basically, denser chips generate more heat in the same space. Heat sink is one solution; heat sink with a fan is better, water-cooling even better. There are others, usually more expensive (like super-cooling).

[teh_lurv]

There used to be a good video out there on the web of a dude pulling the heat sink off of an early 2000s AMD chip while using a laser temperature sensor. The temperature skyrocketed and then the CPU lit on fire.

 

Those old AMD CPUs had no built-in thermal protection, so they'd happily run at full speed until they melted. Intel CPUs then-and-now (and I believe modern AMD CPUs too) will severely throttle themselves down if the CPU's internal temp sensor goes past 100C or so.

[CatPix]

Modern MAD have it. early CPU didn't had thermal detection... Can't tell about the Pentium I and II, but from this generation, the Cyrix CPUs didn't had protection either unless I'm wrong.

[Osgeld]

Note that some CPU of the time needed them already, the Bally Astrocade boards need at least one heatsink, and when you have one running, you feel that adding a heatsink on the other chips can't hurt.

Some models of Intellivision are prone to overheating too, and adding a heatsink to the CP1610 can't hurt either.

 

Heck most of the chips in a 2600 make you start to wonder if they need them as hot as those old TTL things got

 

Modern MAD have it. early CPU didn't had thermal detection... Can't tell about the Pentium I and II, but from this generation, the Cyrix CPUs didn't had protection either unless I'm wrong.

I know my first gen ceramic 90 mhz pentium doesnt It will run without thermal management until it crashes

[7800fan]

I think I know of that AMD video. The laser sensor showed the temp had jumped to over 600'C in just a few seconds and cooked itself. Intel had thermal control and when the heatsink was removed, the temp didn't get past 100'C and the CPU slowed down by a lot almost to the point the game was unplayable. Putting the heatsink back allowed the Intel CPU to resume full speed soon after.

 

I think it was Pentium 4 that first had throttling for heat control. Earlier Pentium just shut down when it got too close to critical level.

[edweird13]

There used to be a good video out there on the web of a dude pulling the heat sink off of an early 2000s AMD chip while using a laser temperature sensor. The temperature skyrocketed and then the CPU lit on fire.

This video was on tomshardware. And I can say from experience this is true. Way back when I went with an AMD xp1700. It was my first AMD CPU. I got all the parts in the mail and assembled it. Booted the system and started installing Win XP. Thought I would take the dog for a walk while windows was installing. Came back from my walk and instantly smelled the burnt electronics smell. Looked inside the case and the heatsink had fallen off and let the smoke out. Fried CPU and motherboard. It was the only time I ever owned an AMD. Went back to Intel shortly after that indecent.

[Osgeld]

I have never had one go haywire on me course the boards I bought back then had the thermal sensor in the socket and would plain old shut off once it hit a threshold set in bios, but usually your lower grade or high price tweaker boards wouldn't

 

On the flip side I got a core2 in "well sometime last year it got slower and now it's just actin weird" sigh

Edited August 6, 2016 by Osgeld