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AirJet makes a MacBook Air perform like a MacBook Pro (macworld.com)
200 points by MBCook on Nov 27, 2023 | hide | past | favorite | 119 comments


There was a hack (using the most liberal idea of a hack) a few years ago that was even simpler: just put a thermal pad into your MBA. Apparently it still works.

https://forums.macrumors.com/threads/m1-air-with-thermal-pad...


To pre-empt the inevitable question about why Apple didn't do something so seemingly obvious: it's a trade-off to avoid the device getting uncomfortably, maybe skin-burningly hot under load.


Even a very reasonable CPU temperature under load like 60C, you can only touch a surface that hot for about 5 seconds before being burned.


Indeed, there are also surface temp regulations for consumer devices (eg why certain action cams shut down much earlier in the EU)


Reading that thread it also seems to heat the battery more, prematurely degrading it.


Yep, can confirm this works great in the M1 Air. I've been running mine this way since I got it way back in 2020. Greatly lengthens the time you can play graphics-intensive games before thermal throttling starts to occur and your frame rate goes choppy.


I wonder what the performance improvement would be for a newer PTM7950 thermal pad. These have a different chemistry versus traditional thermal pads. They actually get better over time.


That would be way too thin. PTM7950 is not intended to be used as a thermal pad.


How do you find surface temps under non-gaming loads, i.e. does this limit your use of the MacBook to desk only?


If I'm gaming I do usually use it plugged in to my external monitor with a mouse and keyboard, and the lid closed. And it certainly does get quite warm during extended sessions, but not blazing hot like my previous Intel MacBook Pro did.

Under non gaming loads (for me, that's mostly web, iOS development in Xcode, and streaming movies/TV) the M1 Air barely ever gets even slightly warm.


That’s great. Thank you.


While this benefits performance it does hurt the battery because the battery suffers from the heat of the chassis. And of course like others already mentioned you can’t comfortably touch the bottom of the laptop.


This hack will always work, they must thermally insulate the laptop case, otherwise the laptop is a huge burn hazard. About 43 C is the threshold for pain, anything above that will cause burns.


In my experience, even with the thermal pad installed, the M1 Air does not generate anywhere near enough heat to become a burn hazard. It can get pretty warm under heavy GPU loads, but not scalding hot like previous-generation Intel MacBooks.


> if Apple were to use AirJet instead of the fans it uses in the 14- and 16-inch MacBook Pro, it could free up space that the company can use for, say, a bigger battery.

No, they can't put a bigger battery. The 16" MBPs already have a 100 Wh battery, which is the maximum size allowed by the TSA [1].

[1] https://www.tsa.gov/travel/security-screening/whatcanibring/....


That link is for spare batteries. I believe regulations differ for "installed" batteries.


I’ve been following Frore Systems (https://www.froresystems.com/) for a while and have wondered if Apple might consider acquisitions of next-gen components like theirs. Presumably Apple wants to wait for them to be proven in production first, but can you imagine an even more power efficient and silent cooling system on MacBook Pros? That would get you current M3 laptop performance in a form factor closer to the last Intel generation MacBook Pro (slimmer).


I would feel physical pain if apple locked in tech like this. So dumb and annoying that we have to cripple so many potential applications just so apple can exclusively put it in a couple high-end laptops.


I think if the tech does not get acquired by someone big you probably will never see it come to market in any meaningful way. AirJet should just let people buy these for DIY to start and build hype and start partnering with OEM’s for preconfigured options.


DIY is probably the worst option from the business perspective or AirJet.

The market for that is minuscule, and they likely can't make a solution that works universally for every laptop.


>I think if the tech does not get acquired by someone big you probably will never see it come to market in any meaningful way.

Why? They should be able to acquire purchase agreements and startup investment on the strength of the product.


> So dumb and annoying that we have to cripple so many potential applications just so

My brother in christ, have you heard of the patent system in general?

Try starting a new phone or laptop company. Your step 1 will be to acquire a patent war chest, so if someone sues you for patent infringement (and they will), you can sue them right back for the same.

In this world, if that company is for sale, someone much bigger is going to buy it, and make their technology their own exclusive. Be it Apple or Samsung or whatever. Getting hands on this tech _so your competitors don’t_ would also be a valid reason for acqusition.


Shh, any louder and you'll rouse the Butterfly keyboard or the Touch Bar from their graves!


What about the FingerWorks TouchStream? sigh


They’re moving air through a channel that’s about a mm high, yet claim “dustproof” on that page. Is that realistic?

Also, could a hacker build something like this (but likely much less efficient) at home by taking apart a DLP video projector and playing a carefully constructed video loop on its micromirror (https://en.wikipedia.org/wiki/Digital_micromirror_device)?


According to LTT video, the 10x static pressure allows for dust filters.


such claims without tests to validate are kind of useless. they're just taking the company at their word.


They’re already in a commercial product:

https://www.zotac.com/us/page/zbox-pico-PI430AJ-airjet


you've misunderstood my point -- I'm saying manufacturer claims need to be verified. 10x doesn't mean all that much to begin with and, moreover, fan static pressure claims from manufacturers get verified by virtually no one. a shady manufacturer could straight up make up these numbers and no one would be the wiser because of that lack of independent verification. it's like if a CPU GHz figure was taken at face value, without testing.


where can I buy this?


The Linus Tech Tips video says that it's a commercial product for use in factories where dust and other airborne material mean they can't use fans for cooling (apparently, similar previous products from this company used passive cooling).

However, the marketing images on the product page don't match with this; there's definitely a lot of images of use at home. I'm not sure whether it's a consumer product or not.


For small companies/startups, selling a niche product, direct to consumers is rarely worth the time. You have a small team that should be putting their effort into selling/packaging thousands with each call, not 2. The company lights only stay on if the collective sales goals are met. And, shipping to Joe Shmoe can easily cost money. This is why places like Adafruit exist: direct-to-consumer is a huge pain.


If the product was any good, Apple would have already signed an exclusivity deal and NDA. If they didn't, another manufacturer would have.

The fact that hasn't happened, either means the product has a big downside (eg. stops working after 1 hour use as it blocks with dust), or because the manufacturer is offering silly terms.


It’s brand new, it was shown at CES. I think they’ve worked with one PC OEM but their devices are designed for much lower heat output at the moment than what a MBP generates.

I suspect it’s more of a “does it work, how does it hold up, and can they scale to our volumes/heat levels” question.

The fact they could hack this is still interesting. Fun to watch.


I still haven't heard the fans of my 14'' M2 MBP. And it's the thinnest laptop I've ever owned.


I currently have the 2019 16” MacBook Pro and it’s thinner than the new chassis. I like the form factor better, though I’ll likely upgrade soon happily for better performance and power efficiency.


As cool as this tech is, I question the efficiency. They claim '10.5W of heat removal using 1.75W of power' in their press release. I'm not entirely sure how this compares to regular fans, but data points I can find suggests that regular fans use much less power (even the tiny laptop ones) for similar amounts of cooling performance. Could possibly be very cool for a tethered application (mac mini, mac studio?), but increasing power draw seems like it'd be a bad thing for battery life.


I doubt Apple is all that interested in something like this for the Air because they have a faster, actively-cooled laptop available - the MacBook Pro. The Air is their light-duty, fanless machine and I doubt they are all that interested in changing either of those qualities.

It would be nice for consoles and other living room electronics. My PS5 fans are annoyingly loud.


Why is this downvoted? It's speculation and may be wrong (I don't think it is), but it's a perfectly legitimate thought that any other company on the planet would receive from HN without the downvotes.

The downvoting anything critical of Apple is getting ludicrous. Maybe you believe they are a benevolent user-loving company who always does what's best for their users regardless of how it affects their business, but viewpoints who don't share that position aren't automatically wrong because they have a different opinion than you. Skeptical people are what built the hacker community. If you don't want to embrace that spirit, at least don't try to silence it.

Edit: And yes, whether Apple would want this or not is very relevant, because if you read the article, they do not sell to consumers. The only customer for this would be Apple, and having Apple buy their product and put it in macbooks is the strategy they are pursuing.


1) it's not downvoted

2) it's not critical of Apple


> 1) it's not downvoted

To quote Doc Brown, "you're not thinking fouth-dimensionally!" It was when I posted the original comment.


You can make large fans quiet, people do it all the time... it's just a design choice to not do it (since usually it involves size tradeoff). I assume this would be quite expensive to cool a PS5 though, since PS5s need hundreds of watts of cooling (so, you'd need like 20 of these modules?).


> You can make large fans quiet, people do it all the time

This is unintentionally funny, because the law of fans is that the smaller they are, the louder they have to be to achieve the same cooling.

Air moved is a function of blade size and speed (and shape and count and more, all applying to big and small fans ~alike) — and those two are indirectly proportionate. The smaller the blade, the faster you have to spin it. The faster you spin, the more turbulence you make, the more sound you get.

Biggest hack for silent active PC cooling is to use upsized fans spinning slower (see Notcua).


Understood, however the PS5 uses a single giant 120mm fan (120x45mm) which should in theory be quiet. It's much larger than the fans used in many consoles. And yet... I'm not sure what other constraints caused this trade off.


The PS5 uses a centrifugal blower rather than an axial fan. Blowers can push air effectively through restrictive heatsinks and vents, but at the cost of greater turbulence and therefore noise. The Xbox Series X/S consoles use axial fans that move a lot of air at low RPMs; this requires large intake and exhaust vents and an optimised internal layout, because the flow rate of an axial fan falls rapidly as static pressure increases.

The PS5 is fairly loud, but the noise is quite directional - it's much louder from the rear than the front. By keeping all of the vents on the front and rear of the console, it can work effectively inside a TV cabinet or media center that would suffocate an Xbox. It's not the set of tradeoffs I would have preferred, but it isn't a thoughtless design.


One fan might not be enough for the amount of heat generated. The airflow engineering could be very poor, requiring high velocity and not just high cfm to overcome. It could be positioned poorly or attached to a skimpy heatsink to save on copper (or even worse, to save on another metal). The hottest components may have very small surface area so they don’t diffuse heat efficiently. Lots of reasons, usually having to do with thermal engineering not being a priority until late in the game.


Why speed up the cheap model when we have a faster model for more money?!


Silence is part of the Air's appeal, as well as the shape which wouldn't allow for an internal fan


IIRC, LTT did a video touching on these a bit ago and said there was still a noticeable hum (at an annoying frequency), so the noise savings might be less than you'd expect.


Is your PS5 dust-clogged? Mine is effectively silent.


Unless it's calmed down since launch, PS5 noise is all over the place. I don't usually hear fan so much as coil whine on mine though.


I don’t think so. I just got it back from Sony and I would guess that when they replace the power supply, they would also blow out any dust.


at the very least, getting at the fan for cleaning is toolless. they really learned their lesson from how bad some ps4s got.


It seems like the kind of thing a company like Apple could acquire, tightly integrate, and squeeze out a small margin above existing tech on a couple axes (eg. maybe it draws more power but makes room for a bigger battery, or maybe software can hyper-optimize when and how it's turned on)

Seems like a harder sell as an off-the-shelf component. I wonder if they're angling for an acquisition (by apple or otherwise)


Apple have already shown from their crippled Intel Macbook Pros that they care nothing for good cooling systems, and are more than happy to accept sub par performance as long as the design of the product is right. I cant see them jumping at the chance to aquire a cooling device company.


This smells _exactly_ like a move to drum up acquisition talks.


Exactly my read as well:

> AirJet isn’t a consumer product–consumers can’t buy it and modify their own MacBook Air, nor does Frore plan to create a kit for consumer sale.

This is aimed at Apple, and he doesn't want to offer it for sale? Acquisition.


That ratio is pretty okay for a laptop... Sure, it's far worse than fans, but you are only paying for all of that 1.75 watts when at full CPU load for extended periods, which is rare.


You are trading some efficiency for smaller size.


Note that they also had to drill vents into the laptop and use the speakers as outlets.


I've been pretty excited for the airjet to start making it into products but also I hope they open up D2C orders for tinkerers soon. As a normal consumer I can buy every other part of my laptop or desktop all the way down to most individual electrical components.

I get that it's a new product that requires good engineered integration to really show off how amazing it is, so they want to start with some flagship products... But if Frore Systems starts treating the airjet like it's a secret sauce to be slowly doled out to manufactures it'll just make me suspicious of their claims and the airjets real world usability.


For people interested in the Frore system, Linus Tech Tips did a video on it: https://youtu.be/vdD0yMS40a0?si=UwAeqbTxxnDRf1_V.


They just released a new video about it.

https://www.youtube.com/watch?v=ji5kZ3VdFDY


FYI: This is a proof of concept, not a product, not a product announcement.


I used to set my MacBook Pro on ice packs when working on certain processor-intensive tasks... Seemed to help!


Doesn't this cause condensation?


Yes. I broke my Mac a few years back this way


What if I put something inbetween, like a cloth. So only the cold temperature radiates through?


The problem is the condensation of the humidity of the cold air inside of the device, not the humidity of the condensation on the cooling pack itself.


piezoelectric cooling has left a history of ruins because it doesn't account for condensation, particularly in small, consumer-grade applications where drainage paths are hard to design for. You need one drop of water in the wrong spot. Not a game I'd play with a metal-cased laptop, personally.


Are you thinking of thermoelectric/Pelletier cooling?

Piezoelectric cooling doesn’t cool air so there’s no chance of condensation.


Would placing the air on top of an ice pack temporarily improve performance? For example when needing to render a video?

Don’t judge if this is a very stupid question - about to buy a MacBook Air to substitute an M1 Max for travel.


Yes. The aluminum chassis is basically a heat sink. The underside of the M1 Air heats up when the soc is under load. Cooling that spot will help cool the soc.


If the chassis were a heat sink, it would be a serious burn risk.


That's basically why it throttles.


It’s not directly connected to the CPU, but it clearly gets quite hot.

Removing that heat should be beneficial either way.


Sort of. The problem is that the chip is what needs to be cooled, and that is separated from the ice pack by a thermal pad and the laptop case.

both of those are way less efficient than something that cools the chip directly


Iirc, an issue with this and e.g putting it in the fridge is potential for condensation. Probably worth looking into before putting your machine on ice.


Not really, thermal conductivity between CPU and outer layer is not best. M1 is OKish, M2 are really bad.


I think I saw that they added little standoffs on the M3 between the case and the cooling mechanism to help prevent the case from coming into contact and getting too hot.


My 2015 13" MacBook Pro spins up fans hard just to check email. Maybe it's the aftermarket OWC Aura Pro SD I've got in it? As soon as I run VS Code with a Firebase emulator it starts throttling down.

I'd love to get this Airjet thing installed in it to see if it makes a difference.


With that laptop now being 8 coming up on 9 years old, I wouldn’t be surprised if its thermal paste has dried out, which means that heat isn’t being transferred away from the CPU into the heatsink as effectively, resulting in the fan running harder. If you want to keep it going a while longer it might be worth picking up a tube of Arctic MX-4 and replacing the stock paste, cleaning out any accumulated dust in the process.


The Intel Macbooks had woefully underdesigned cooling solutions. They're also less efficient than the model demonstrated here.

This "airjet" is a kind of almost solid state fan using membranes to generate airflow. They may be able to perform similarly to normal fans with less noise and a smaller physical footprint, but they still need to get that air moving through a heatsink somehow. I don't think it'll work for laptops that are designed to thermal throttle after a few seconds.


A 2015 MacBook is also approximately 10x less powerful at max capacity than a 2023 laptop, so it has to work much harder to achieve the same result.


I have the 2015 15" Retina MacBook Pro. I've loved this thing and it's worked great while letting me play a couple of the Mac supported steam games ever since I purchased it. But man I empathize with you about the fans turning on almost immediately after turning on. Lightroom finally became unusable because the slider changes would lag for every single photo and Xcode no longer supports iOS 17.

I jumped to a 16" M1 Max that I found at a pretty decent sale price. You won't regret it if you can swing the cash. The fans have only turned on when I've played Civ 6. I think they maayyy have turned on during Lightroom use but I'm not so positive.

It's said because my old 15" still operates, hardware wise, without any issues. I plan to turn it into a linux or a windows machine to play other old computer games.


You can roll back to a pre-mitigation, pre-apfs build of MacOS (≤10.13.2) to restore performance.

https://support.apple.com/en-us/103239

Or, switch to Linux and use mitigations=off.


The 2015 models used 4th gen Intel chips which ran quite hot. And the cooling system on those models is super noisy.

Just get an M1 Air on sale, second hand, or refurbished. It will be night and day.


I have a 16” M1 Pro as well and it’s night and day. But I still love my little 13” 2015 Pro- there’s something comforting about it.


Get an Apple Silicon Mac. The latest Sonoma beta has a bug that makes every WebView use 99% CPU all the time, and the fans don't even spin :)


When was the last time you opened it? In my experience it is just dust/hair in the fans.


I have a 2019 16" i7 pro and a M1 Air. The 16" is always warm even just idling, and the fans go when you do anything more intense that basic terminal tasks.

Air gets warm only with some long compiling.


My 2012 17" MacBook Pro video card died about 2017 but even then and even when new the fan was on a lot. HD was SSD, lots of RAM, discrete GPU but overall the thing was toasty.


If I understand correctly, CPU clock speed is really relevant only for bursts in CPU use. Any meaningful steadying of processing speed at that peak,or near it, seems to be a question of power efficiency and cooling in tandem.

So now if Apple is well ahead of the competition in power efficiency, and if, on top of that, the Aijet is really a revolution in (silent?) cooling, then we have here a maximization of the value of all those Ghz.

As an amateur computer musician, this is exactly what I need: a continuous silent performance at a "budget" price.


There's a couple wrinkles here. For one, power efficiency varies with temperature, keeping chips cool, increases their efficiency, although you'd need a lot of data to determine if watts spent on cooling were comparable to watts saved by being cool at a given performance level.

The other is Apple chips target a lower clock rate than Intel and AMD do for laptop chips, this is a tradeoff. You get better perf/watt at lower clock rates, and a lower targer design can be smaller[1] and lower power. OTOH, you miss out on the top end of performance for those willing to power and cool the beast. It's a good tradeoff for Apple, who never provided ample cooling for their Intel based laptops, but it's hard to market for Intel and AMD when PC laptop makers do want to sell some devices that can clock to the moon all day if users want it. AMD is expirementing with their compact cores as power efficient cores in some laptop skus, so we'll see something there; Intel is going with the BIG.little approach of less capable little cores, rather than just clock limited little cores.

[1] see AMD's Zen4c which is about half the size as a regular Zen4 for the core+L1+L2, L3 cache footprint remains the same for a given size


On many laptops you can disable boosting speeds and lock down the frequency (thermals permitting). I don't know if Apple's devices allow for such measures, but close-to-constant performance without fan noise can be a matter of configuration.

You can try running these chips at their boost clock all the time by attaching coolers, but the hardware wasn't designed for that and neither was the software. It's easier (and more power efficient) to clock down if you care about maintaining a set speed. With a battery capacity designed for short bursts, you'll also lose out on battery life if you decide to crank the hardware.

The Macbook Air and its competition (MS Surface etc.) are completely silent because they are fanless, and I don't expect their performance to be inadequate for anything but the most CPU intensive tasks. The Airjet will add some airflow, so while the difference may be minjmal, it'll always end up louder than before.


Can anyone explain how "tiny membranes that vibrate at an ultrasonic frequency" is able to produce "AirJet’s 1750 pascals of backpressure" which is "more than 10 times the suction force of a high-end notebook fan"?

I understand how you could have a bunch of membranes that vibrate ultrasonically -- it's basically an array of miniaturized audio speakers. What I don't understand is how any localized oscillation of air gets transformed into massive, consistent air suction in a single direction.


The answer, as you might expect, is "valves" as part of the integrated MEMS :) https://patents.google.com/?assignee=frore+systems


"valves" is a good short answer. If you want a long explanation, this video gets into a lot of details. https://www.youtube.com/watch?v=vdD0yMS40a0


Thanks, but the video doesn't actually explain it. It explains a lot around it, but it just says that the chip uses a "piezoelectric fan" and shows the intake slits and the outtake jets, but I'm still not finding an explanation of the mechanism itself.

I can vaguely imagine how valves might work, but I'm still curious how they do. I looked at the linked patent applications but the descriptions seem way too complex and abstract to get any kind of intuitive sense of the mechanism without already being an expert.

There's a related video they link to: https://youtu.be/NY-gA_zA_os?si=9ULOds_TqUO56MGs which demonstrates one type of piezoelectric fan, but it seems to be operating on totally different principles -- one end is freely swinging, rather than a membrane with fixed edges oscillating. And there are definitely no valves involved in that one.

Is there anywhere else that explains how oscillating membranes generate smooth airflow?


if you look at the images in this particular patent of theirs, I think it helps understand what you're asking about: https://patentimages.storage.googleapis.com/93/1e/5d/6ad89e2...

Hope that helps!


my guess would be that they move an absolutely tiny amount of air, and pressure is force * area. They explained that since air is a very poor conductor of heat, most of the heat tends to pile up in a thin boundary layer next to the fins, and just exhausting that will get you most of the cooling performance.


Their business model to try to get Apple to license their tech seems kind of misguided. Why wouldn't Apple simply design their own system? It's one thing to get licensed or acquired by a company worth $100M. It's another to try to do the same with a company worth 10,000x times that much.


If they dont have a patent on this thing then I would be very surprised that they are shouting this loudly about it.


Even if they do have a patent, it seems like Apple has enough lawyers that they could simply build around it. It's a trillion dollar company. They can do what they want, really.


I don't know how it will pan out in commercial products, but it has been a long time that I've been this excited about hardware, it does feel like real innovation for cooling and especially for mobile devices.


Is it audible to animals?


In the video interview on the page they said that it’s something like 25 dB. So technically it’s audible to humans too, it’s just low enough that no one really cares.


In the product page they mention it's 25dBa, but if that's measured using a reference microphone for the human spectrum it's not going to reflect if the ultrasonic frequencies its running at are audible to say, a dog.

The reason I asked is because this is sick, unless it makes my dog cry.


Likely edible as well


Humans are animals.


Domain: Eukaryota

Kingdom: Animalia <----- you are here

Phylum: Chordata

Class: Mammalia

Order: Primates

Suborder: Haplorhini

Infraorder: Simiiformes

Family: Hominidae

Subfamily: Homininae

Tribe: Hominini

Genus: Homo

Species: H. sapiens


Being spared a fan with its noise is the exact reason that I use an MBA. I surely do not want to retrofit a fan. But nice idea anyways to look after your cooling approach.


Frore systems claims 21 dBA. That's about the level in a quiet area in nature without wind. Much less then even a whisper. Unless you are sitting in an extremely quiet room you won't hear it.


Generally it won't spare you of the noise, as the exit velocity of the stream will be quite a bit higher, which will result in a higher pitch, which is quite a bit more noticeable due to the quirks of human hearing.


it doesn't use a fan


Video says it expels air, generating sound at about 25 db, so not much "air noise".


When they write about putting this chip in the MacBook, do they mean physically cracking the device open and putting the chip inside? If so, where does the space come from? doesn't that void the warranty?


While the article itself answers all your questions, the article links to more details at https://www.froresystems.com/blog/how-do-you-cool-ultra-thin...


My "original out of box" OCD couldn't stare at a machine modded like that.




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