M1 Air with Thermal Pad Mod | Hacker News Reader

M1 Air with Thermal Pad Mod

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86 pointsbatterylow41 comments

Linus Tech Tips did a video on this: https://www.youtube.com/watch?v=ghDvyItIHTY

Created labs did a step by step guide: https://youtu.be/IACHo5y9Los

He also referenced the story from 2002 about the man who burned his "delicate bits" with a hot laptop. He suggests it may be apocryphal. I remember that story [1].

The main reason I remember it is because of the reported warning text. At that time, I owned a Dell Latitude L400 laptop, which did indeed come with the exact warning text quoted in the article. It got got far hotter than any other laptop I have used. I have no trouble believing it could burn someone.

[1] https://www.theregister.com/2002/11/22/man_burns_penis_with_...

This is why at Apple the division making MacBooks is called "portables" and not "laptops." They're officially not supposed to go on your lap.

Also the thermal limits of the human dermis are pretty well studied and documented. The vast majority of CE products are designed not to exceed 50°C, which is when the thin skinned (children and elderly) start to get second degree burns pretty fast. 60°C is where you burn almost immediately.

Interestingly 45°C is "threshold of pain" for most folks, but few companies set that as the target limit. Since thermal dissipation is a ∆T game that last 5 degrees matters a LOT for wattage out (on a hot day outside 30-35°C is a good surface temp estimate, so that last five degrees is the difference between 10 or 15 degrees out, a non trivial delta.)

I did this to mine. It no longer throttles under any type of regular use. I did an hour long encode using Final Cut Pro and the hottest it got was 83C. The hottest the battery got was 44C, so it is doing a fine job of dumping the heat outside of the device.

The bottom cover does get hot, but I don't keep it on my lap.

I don't do any gaming with it, but I tested Rise of the Tomb Raider and it handled it very well without throttling. My XPS turned into a leaf blower in seconds with the same game and still managed to throttle at times.

I'd recommend the MB Pro M1 if you want to do longer projects. I'm pretty sure the MBA would become heatsoaked after encoding for a few hours. The Pro has a fan.

It's a good mod that takes a few minutes to do and really delivers.

Apple really killed it with the M1. I have the base model. Affinity Photo is another app that has been optimized for the M1, and in some operations manages to be faster than my 8 core/16 thread Ryzen 3700 with 32GB of ram.

It simply curb stomps my XPS in every single performance metric while being totally silent and never throttling under what I use it for.

Safari has also been tuned for the M1, and it is the fastest browsing machine I have ever used.

I'm contemplating this mod too, what app do you use to measure the temps?

Macs Fan Control is free and, despite the name, works fine on the Air (it just shows a notice that the computer is cooled passively). Also it's a simple move-to-Applications .app, and I like those.

Very nice! Just a note that I had to download a beta version here https://github.com/crystalidea/macs-fan-control/issues/435 for M1 support.

Thermals are fun. Doing video encoding on my Surface Book (i7-6600U) in a 25–35°C ambient temperature, lying its heat source down on a marble floor speeds it up by 60% within a minute or so. (Remember the Surface Book puts its CPU behind the screen, so it doesn’t transfer much heat through the base. This is in its performance mode, where it can get impressively hot for a 15W CPU, like ow-that-actually-hurts hot. But because that’s not the base, I think they weren’t scared to transfer heat to the body, which is what it sounds like this M1 MacBook Air is avoiding.)

I threw my M1 MacBook Air in a snowbank in -11°C last night, let it chill for 15 minutes, then ran Geekbench and Cinebench

Here's GB: https://browser.geekbench.com/v5/cpu/6487568

Cinebench was 7709, about 900 points higher than my usual bench result.

Isn't that dangerous for the screen?

A lot of people are saying "Ok, but this burns your legs/crotch". But could you do this and then better insulate the outside of the bottom so that the heat transfers into the case faster and out of the case slower per square inch? You'd still have an effectively much larger heat sink.

Sounds like it's worth doing if you want to do longer edit sessions with Final Cut Pro on the M1 Air.

I like that you can control how hot the bottom gets by applying more or less thermal pads.

This is a good way to easily give yourself more endurance performance but I wouldn't recommend it - it does make the chassis uncomfortably hot.

Depends on the use-case. If you use your laptop mostly in a clamshell mode connected to a monitor and keyboard, you don't really care about the chassis.

I suppose. There probably is a thin niche that would appreciate the performance gains, but I feel that in most cases you'd rather have a pro or really a mac mini if you mostly use it as a desktop and have a need for sustained performance over time.

Could be both. You can use the computer on your lap if you're doing word processing and checking email, or on a desk if you're editing video.

Right, but it's a pretty scarce section of the venn diagram between

Needs a laptop (since you're not getting a Mini) to use portable

Needs endurance CPU performance (and notices a 15% performance decrease)

Frequently docks laptop during workloads

Can't or doesn't want to pay extra for the MBP

> Frequently docks laptop during workloads

That's not a requirement, you merely need to use your laptop at a desk (or a table, or the seat-back shelf on an airplane) and not literally on your lap. That's usually how I use my laptop anyway, for comfort reasons. Certainly when I'm doing something CPU heavy, since I don't generally edit videos on the subway.

I think the other three requirements are perfectly common.

its 7 degrees over the recommended upper limit per regulations. Linus Tech Tips highly recommends it, its not scalding hot and I wouldn't call it "Uncomfortably hot".

It gets toasty if you run long workloads.

Presumably my existing MBP 16" is within regulations, but it can get uncomfortably hot in my lap.

Don't think I'd want 7º over that.

I can handle more heat than you can perhaps? I also have MBP 16" 2019 version and it gets no where close to any uncomfortable region for me on full throttle. I also drink my coffee scaldingly hot :)

Just don't sit it on your lap.

The trick is to make good skin contact with your legs before you heat it up. You are a mammal and can easily dissipate over 100 watts, it is your human super power. The bottom will only get a bit warm as you pump away all the heat.

In days of old I used to keep the fans from coming on for an aluminum PowerBook with this trick.

The human heat sink. Sounds like something from The Matrix.

You can even lose weight this way!

(I’m mostly kidding but not entirely. Most of our resting state calorie consumption is spent on thermal homeostasis, and the greater a temperature gradient your body needs to overcome whether to warm up or cool down, the more calories it’ll burn in doing so. Although if you’re sitting in the freezing cold or in an air conditioned room and putting a warm laptop on your lap, you’re probably going to be burning fewer calories since you’re nudging your body temperature in the right direction.)

I am convinced this is why children get so dead-tired after the swimming pool - even if only wading around. They have a small body mass and they need to regulate a ~20 degree temperature differential ...

That’s a logical enough deduction to file under “accept as scientifically valid unless and until proven otherwise,” at least as far as I’m concerned!

> whether to warm up or cool down, the more calories it’ll burn in doing so

To warm up yes, but to cool down? How would it make sense to generate more heat (burn calories) to cool down?

Our bodies are less efficient but no less incredible at lowering their temperature as they are at raising it. See for example the production and excretion of sweat takes energy, as does increased heart rate to improve circulation in an attempt to a) handle/average out local hot/cold spots, b) improve shedding of excess heat via radiation in the extremities, which is one of the reasons we have weird thin, fin-like protrusions sticking out of our heads on either side: pumping blood through these thin slabs with high surface area gives maximal chance to reduce the temperature of the blood as the air flows over them. Again the the same with the upper and lower extremities, which radiate heat at greater levels than the trunk. Also, increased, shallow breathing to attempt to cool down blood circulating in the high surface area exposed in the alveoli of the lungs (which is normally why exhaled breath is much warmer than the local air temperature). There are other mechanisms as well, I am by no means an expert but thermal homeostasis is of extreme importance and we’re quite good at it - and like any other physics process, heat exchange is a form of work that requires the expenditure of energy.

I remember reading a study that for male laptop users the extra heat has a small but real impact on fertility

Ouch, is that where the heat dissipates from?

A bonus, though a very small and unreliable one.

Better to just get the hardware upgrade. It's pretty quick and seems harmless.

Seems like the difference between thermal throttled MBA and non-throttled MBP is ~15-20%..?

the question I have is:

Is the mac mini similarly affected?

No, the Mini has a fan and a hilariously large enclosure for airflow. Both the Mini and Pro have no trouble sustaining loads indefinitely.

Folks, keep in mind that you're doing this to something containing a lithium battery. If it explodes, your hot case is going to get far hotter. Please be cautious.

A brief FAQ list to address the predictable replies:

Q: But it hasn't burned anyone!

Yet.

Q: It won't, obviously!

And yet, it might.

Q: Nonsense!

You're thermally overclocking a physical object that happens to contain enough charged lithium to kill a small household.

Q: I know what I'm doing!

Then you put a "heat warning" sticker on the top cover, right?

Q: Of course not, that would make it ugly. And anyways I don't have one.

So you're consciously choosing not to take appropriate safety precautions?

Q: They're not appropriate.

You don't know what you're doing.

Q: Safety precautions aren't that big of a deal, it's just a few degrees warmer!

Are you familiar with the phrase "served as a lesson to us all"?

Q: A comment on the Internet said that it's safe to use my bare legs as heatsinks.

"Served as a warning to others".

Q: But I know how to apply thermal paste properly!

All the better to injure yourself and your property with.

Q: I have the right to modify my own objects!

And, in return, you grant those objects the right to harm you if your modifications introduce drawbacks.

Q: That's impossible!

Nothing's impossible when it comes to people modifying things while thinking they know better.

Q: It's so low of a likelihood that I'm willing to take my chances.

That's your right, as long as the object isn't in the vicinity of other human beings at any point in its modified life.

While you are right and I applauded your caution.

It is also fair to note that no (electronically non-conductive) heat dissipation mod is likely going to cause a runaway thermal event hot enough put the kind of stress you are talking about on a battery, at least not on an M1 Air. If you were using liquid metal and it caused a short, sure, but that is a regularly occurring issue with liquid metal.

This is an electronically non-conductive thermal pad with, what do you figure, a 5w/mK thermal conductivity? On a device that probably never cracks 15w peak. And you can bet if it does, it would only sustains that output on the order of seconds.

That said, I'm all for stopping unskilled people from attempting unsafe things. But then again, doing those sorts of things would sum up my hobbies neatly.

Your comment gives me hope that this is safe. I wish I’d seen one like it sooner, or I might have been less cynical about this out of the gate. It just stresses me out to see people going in blind. You’re not. Thank you.

This comment greatly depresses me. You are pretending as if batteries are volatile bombs. They are not. They can generally handle temps of upto 55 degrees fine. And guess what. They include thermal sensors.

This mod is so low risk for the battery it might as well be almost 0.

You're vastly overestimating the temperature sensitivity of lithium batteries. They explode due to short circuits (allowing the stored energy to be quickly converted into heat, also heating the battery itself in the discharge process), not a simple warm-up to 60°C.

For comparison, leaving your laptop (or cellphone) on a car's dashboard on a sunny day is more dangerous than this; with very bad luck (and dark colors) you can almost get water boiling there. (Quick googling says 90-95°C.)

FWIW though the higher temperatures will degrade the battery quicker.

For reference: (tested at 130°C, safety limit at 100°C, operational up to 60°C)

https://www.orbtronic.com/content/samsung-35e-datasheet-inr1...

9.4 Heating Test

Test method: To heat the standard charged cell at heating rate of 5°C per minute up to 130°C and keep the cell in oven for 10 minutes.

Criteria: No fire, and no explosion.

...

8.7. Caution - The Battery used in this device may present a risk of fire or chemical burn if mistreated. Do not disassemble, heat above 100°C or incinerate.

...

The battery can be used within the following temperature ranges. Don't exceed these ranges.

Charge temperature ranges: 0°C ~ 45°C

Discharge Temperature ranges: -10°C ~ 60°C

Store the battery at temperature below 60°C

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