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Comment by julianlam | Hacker News Reader

> Note that high temperature on the right side appears to be ignored by the OS. Plugging everything into the two right ports instead of the left raised the Right temperatures to over 100 degrees, without the fans coming on. No kernel_task either, but the machine becomes unusable from something throttling.

I feel like the top answer is missing the forest for the trees. If the temperature of the chassis rises past 100 degrees because a peripheral was plugged in, and degrades performance if all of the peripheral ports are in use... that's not a usable computer.

Edit: Ah, 100F is 37C, so that's not so bad.

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A long time ago (roughly 2012?) I owned a Macbook Pro for a brief time

I was running Windows 7 in Bootcamp and I wanted to set up Gentoo Linux in a virtual machine for some Linux work I needed to do

I left the machine on my desk to compile a kernel. Basic wooden desk, nothing underneath or around it. No problems there

Roughly 5 minutes later, the system had reached what Speccy reported to be a scorching 117 degrees celsius! (242.6F)

I immediately shut it down and left it to cool off, then asked around on an IRC full of various flavours of IT people (programmers etc)

The horrifying answers I got were that this was INTENTIONAL and that "the system acts as a giant heat sink" which is why it didn't power off after crossing a threshold

As far as I understand it, running it under Bootcamp also disabled any kind of thermal throttling and forced the more power hungry "Radeon" graphics chip to be used, further adding to the problem

I remember those macbooks got so hot that it was physically painful to touch the metal under the screen near the magsafe charging port. That was fun.

I have forever been leery of hitting the F4-F8 buttons because of the 2007 Core 2 Duo model. I used it for a couple years and remember at least 3-4 times when I decided to rest a finger up there and ended up getting scorched.

Yup I remember this. The area above the F keys would downright burn.

This is why Apple stopped describing their portables as “laptops” some time in the early 2000s. They didn’t want the legal risk of somebody burning themselves after it was implied to be safe to use on their lap.

Well, it was 117 C. If you spilled water on it, it would boil.

Hell, boiling water would cool the machine.

If you spilled water directly on the CPU, maybe.

I have some golden memories from university playing Unreal Tournament 2004 on my laptop in bootcamp, the added difficulty was that if you touch the metal between the keys it'll burn your finger tips.

It's gotta be 100°C.

The top cover part between the touch bar and the screen regularly runs so hot that touching it really hurts. Can't leave my hand on there for more than a second or two. Ran all sorts of diagnostics and according to those everything is fine.(MBP 2017)

I mean, this is in a sense a known issue: https://www.penny-arcade.com/comic/2009/01/30/the-new-hotnes...

Note that was back in 2009. Macbook thermals: not good.

Goes further back than that. I used to refer to the Powerbook G4 as a liquid cooled laptop -- where the liquid was the user's circulation.

At a certain point, Apple had to stop calling them "laptops" and start calling them "notebooks" because people kept putting them in their laps and frying their genitals.

No it's got to be C. 100F is at most, luke warm.

100ºC is boiling though. You would probably smell solder rosin!

Edit: Well TIL there is an awful lot of heat to get rid of.

Some low-temp solders melt as low as 140C, but typical SAC lead-free solders you'll find in laptop motherboards melt at 220C. Many laptops are fine if a processor core hits 100C.

I've got an old Thinkpad with an i7-3920mx that regularly runs at 95C when running a few VMs and is certified by Intel up to 105C. And yes, I've tried replacing the thermal paste and increasing fan speeds to try to keep temperatures down, because not all processors are successful there, but it has been running like that with no issues for years.

That's not too high, considering CPU start to throttle at approx 95C, and MOFSETs can go up to 115C

MOSFETs can go way, way higher than that. There are CPUs (well, microcontrollers) that go way higher than that.

https://www.digikey.com/catalog/en/partgroup/ht83c51/40264

> Specified Over -55 to 225°C

> Typically, parts will operate up to 300°C for a year, with derated performance.

Whether 100°C is fine for a CPU is a question for the individual CPU.

Thank you. I used to design microprocessors (a LONG time ago) and TIL that there are CPUs that can operate at 225°C. Wow. And even limping along at 300°C? Wow wow. BTW, I can't stand the 8051 architecture, but that's really off topic. I guess if you need 225, you need that chip. Reminds me of the Henry Ford / Model T quote...

8051 can certainly service interrupts quickly and predictably, which is probably all you want if you are sticking a microcontroller inside a turbine engine or oil drill.

>and MOFSETs can go up to 115C

Mosfets have a maximum junction temperature of about 175C

Depends on the MOSFET, of course. Some MOSFETS will run up to 300°C, according to the manufacturers.

https://www.digikey.com/product-detail/en/HTNFET-T/342-1091-...

Used in e.g. turbine engines, instrumentation in oil wells or mining operations, and industrial process control. You can get microcontrollers that work in similar temperature ranges, “in any architecture as long as it’s an 8051”.

100%, I should have said "depends on MOSFET" instead of just moving the bar.

Lots of people run video cards up to 95C. Maybe not something I want sitting on my lap though.

My R9 290X stock would run up to 96C.

Boiling for water. Don’t think your motherboard is made out of that :)

I've run CPUs at 100 C. It's not like they melt at that temperature or something.

100C is where intel typically throttles down clock as a life saving measure. You can run at 100C, or higher, but modern CPUs will cut down performance in an attempt to lower temp. High temp = shorter life. Macbooks adjusted that limit upwards so the CPU has a higher threshold before the auto-throttle kicks in. More about that here: https://www.youtube.com/watch?v=947op8yKJRY

What part would thermal throttle at 37C? It can’t be fahrenheit.

It's definitely C, look at the other temperatures. It starts at 25ish C, room temperature.

Let's remember that even though the CPU in a current model MacBook Pro might reach 100 degrees C, the laptop itself is only going to hit about 50 degrees. Which is still pretty hot.

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