[HN Gopher] Building a macOS app to know when my Mac is thermal ...
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       Building a macOS app to know when my Mac is thermal throttling
        
       Author : angristan
       Score  : 205 points
       Date   : 2025-12-28 11:51 UTC (11 hours ago)
        
 (HTM) web link (stanislas.blog)
 (TXT) w3m dump (stanislas.blog)
        
       | Neywiny wrote:
       | Seems like good work. From what I've heard developing on MacOS
       | has not gotten easier over the years. I do question the point,
       | though. I suppose there's merit in knowing if your configuration
       | causes thermal throttling, but what are you able to _do_ about
       | it? There 's no fan profile to tweak or anything. Can you
       | undervolt them?
        
         | amelius wrote:
         | You can move to a colder place or turn the room temperature
         | down.
        
           | nottorp wrote:
           | In the northern hemisphere you can just open a window at this
           | time of the year.
           | 
           | Remember to put your coat and hat on!
        
         | angristan wrote:
         | > but what are you able to do about it?
         | 
         | On Macbooks with fans, I started tuning my fan curve with iStat
         | Menus (https://bjango.com/help/istatmenus7/fans/#custom-fan-
         | curve) because I noticed the default curve was lagging behind
         | and thermal throttling kicked in before the fan even reach max
         | speed.
         | 
         | For Apple Silicon specifically, I recently discovered that
         | there is a "high power mode" (https://support.apple.com/en-
         | us/101613) that allows the fans to run at higher speed. So I
         | don't use the custom fan curves anymore, it helped me a lot
         | (but it does get quite noisy on a 14" M4 Max)
         | 
         | For a Macbook Air, not much you can do besides closing stuff,
         | or elevating the macbook and pointing a fan at it or things
         | like that... but yeah it's a bit desperate!
        
           | somat wrote:
           | An open question on fan curves
           | 
           | Environment: I am currently playing with a pid control
           | function for my gpu fan, that is instead of saying "map temp
           | x to fanspeed y"(fan curve) say "set fan to speed needed for
           | temp z"(pid control)
           | 
           | Question: is there a reason pid type control is never a
           | thermal option? Or put another way, is there something about
           | the desired thermal characteristics of a computer that make
           | pid control undesirable?
           | 
           | As a final thought, I have halfway convinced myself that in a
           | predictable thermal system a map would match a set of pid
           | parameters anyway.
        
             | embedding-shape wrote:
             | > "set fan to speed needed for temp z"(pid control)
             | 
             | Why though? I generally don't care about the specific
             | temperatures of my CPU and GPU, just that they don't get
             | too warm, so for the CPU (AIO) I basically have "0% up
             | until 45C, then increment up to 100% when it hits 90C" and
             | the same for the GPU except it's always at 10%.
             | 
             | I guess I could figure out target temperatures, and do it
             | the other way, but I'm not sure what the added complexity
             | is for? The end results (I need at least) remains the same,
             | cool down the hardware when it gets hotter, and for me, the
             | simpler the better.
             | 
             | I also have two ambient temperature sensors in the chassi
             | itself, right at the intake and the outtake. The intake one
             | is just for monitoring if my room gets too warm so the
             | computer won't be effective at cooling (as the summers here
             | get really warm) and the outtake one is to check overall
             | temperature and control the intake fans. In reality, I
             | don't think I need to do even this, just the CPU+GPU
             | temperature + set fan speed based on that feels simple
             | enough to solve 99% of the things you'd like to be able to
             | do here.
        
               | somat wrote:
               | In my case the gpu fan was not changing speed
               | automatically, (something, something, linux) which I
               | discovered after an embarrassingly long time of poking at
               | other things trying to figure out why my system was
               | crashing so much. And now instead of doing the sane thing
               | and figuring out how to get the fan speed map to work, I
               | thought about it and came to this conclusion "I want my
               | temps to be set value, say 45C, why not use a closed loop
               | controller to find the fan speed necessary for that temp
               | at any load?"
               | 
               | And now am about halfway through building pid fan control
               | software and a janky gpu temp simulator so I can get some
               | intuition on tuning the pid parameters before I set it on
               | my actual gpu. you know, the fun part of computing. But
               | now I am worried that perhaps there is a real reason
               | nobody does it this way.
        
               | embedding-shape wrote:
               | Aren't you ultimately gonna have to figure out why you
               | cannot change the speed on the GPU, regardless of the
               | approach? And then you're just back at square one?
               | 
               | I think no one is doing it that way, because there is
               | simply no need for it. Sure, when I'm 3D printing some
               | material it sometimes need the heatbed to be exactly 45C
               | or whatever, but why would I care about the specific
               | temperature of my GPU? As long as it's not throttled when
               | GPU utilization is at 100%, I'm good to go.
               | 
               | KISS :)
        
               | Forgeties79 wrote:
               | This could be total nonsense and I am definitely out on a
               | limb here, but I remember from my amateur crypto mining
               | days (almost 15 years ago wow) that keeping everything
               | relatively consistent is better for the longevity of your
               | hardware (GPU/CPU mainly). Some people obsessed over
               | getting temps as low as possible but that's not very
               | productive, diminishing returns and all of that. There is
               | just generally a healthy temperature to keep things
               | operating at most of the time, coupled with how hard you
               | push the component in question (while not putting too
               | much strain on your fans either). Basically:
               | swinging/fluctuating is not good, consistency is good.
               | 
               | Again though I could be totally off. I just remember that
               | being spread around as "conventional wisdom."
        
               | embedding-shape wrote:
               | > Basically: swinging/fluctuating is not good,
               | consistency is good.
               | 
               | Yeah, I'd understand not wanting to go between 0C and 90C
               | over and over. But my GPU idles at around 35C, maxes out
               | at 85C or something, and going back and fourth will
               | surely be preferable than staying with a single
               | temperature but voltage clock the card. Especially
               | considering performance.
               | 
               | But again, I'm using my card for ML, number-crunching,
               | simulations and VFX, you might be right that the use case
               | of cryptocurrency mining prefers a different thermal
               | profile.
        
               | The_President wrote:
               | You're speaking the truth, as this is not nonsense - it
               | is correct. At the micro level, thermal
               | expansion/contracting is occurring across the variety of
               | the circuit board materials and components. Hot is fine
               | (not too hot), but it is the consistency that makes for
               | longetivity.
               | 
               | I limit power consumption profiles and clock speeds
               | unless higher power is required, and combine that with an
               | oversized cooling system - keeps regular temps
               | consistent.
        
               | Forgeties79 wrote:
               | Yeah that was my understanding as well. Basically it
               | comes down to how much you are warping/straining the
               | materials. It all seems rather intuitive to me but this
               | is not my area of expertise and just because something
               | makes sense doesn't mean it's correct lol
        
             | kec wrote:
             | PID loops work best when you have active control for both
             | heating and cooling. PIDs are also best when you have a
             | single optimal point you're aiming at, there's a kind of
             | fundamental mismatch here in that there isn't really a "too
             | cold" for your system, you're just aiming to keep the
             | system below an upper limit while hopefully keeping fan
             | noise to a minimum (otherwise you'd just send it and run at
             | max 24/7).
        
               | Espressosaurus wrote:
               | A simple PID wants to keep it at a setpoint, but it's
               | easy enough to layer a target change on top of it, some
               | hysteresis so it's not pulsing on and off, perhaps with
               | control authority depending on the the target, etc. but
               | then that gets complicated and usually manufacturers
               | aren't going to expose those sorts of tunings to the
               | user.
               | 
               | For most people a fan curve is more obvious to work with
               | and it's largely good enough without the irritating
               | behaviors insufficiently tuned control loops can exhibit.
        
             | mveety wrote:
             | > Question: is there a reason pid type control is never a
             | thermal option? Or put another way, is there something
             | about the desired thermal characteristics of a computer
             | that make pid control undesirable?
             | 
             | I've only every seen something like this in _really_ high
             | reliability equipment because they 're worried about
             | repeated thermal expansion causing cracks in the
             | boards/solder joints. There is, often, heaters available
             | for use if the temperature gets too low. For most equipment
             | I think that the juice just isn't worth the squeeze so it
             | isn't done.
        
           | tyre wrote:
           | It would be cool if the bottoms of MacBooks weren't flat and
           | instead wavy or rippling to increase surface area. There are
           | probably a lot of cool designs (ayyyyy) you could machine in.
        
             | Marsymars wrote:
             | There are laptops like that (e.g. the fanless Lenovo
             | Chromebook Plus 14). No idea if it was actually engineered
             | like that for thermal reasons.
        
             | LoganDark wrote:
             | Is there a value to increasing surface area on the top or
             | bottom case of a MacBook? I'd imagine most of the thermal
             | management is achieved by fan-directed airflow through the
             | internal heatsinks and convection through the keyboard.
        
         | jtbayly wrote:
         | I wanted this app to exist. Now it does!
         | 
         | I sometimes face thermal throttling because a process has gone
         | wacko, and all I have to do is kill it. But first I have to
         | notice it.
         | 
         | I rarely notice until half my battery is gone!
        
           | Neywiny wrote:
           | You know what, fair point. I know because my fans go haywire
           | (except that one time my fans decided to just not work until
           | I ran some incantations. The joys of Linux). If you're
           | passively cooled, you get no feedback on CPU load. Makes
           | sense.
        
             | jtbayly wrote:
             | Yeah I'm on a MacBook Air, so no fans.
        
             | angristan wrote:
             | Indeed, that's why apps like iStat Menus, Stats, Sensei etc
             | (for macOS at least) are very useful, I keep the CPU usage
             | and power usage in my menu bar at all times, this is very
             | useful on battery. For example I know that my Macbook Air
             | idles at ~2W-5W, so if I'm doing nothing special and it's
             | using 15W, a process is doing some funny stuff
        
         | nicoburns wrote:
         | > but what are you able to do about it
         | 
         | Quit some apps probably. I often have a bunch of stuff running
         | in the background that I haven't bothered to close yet. It also
         | sounds like it'd be good for detecting software that's gotten
         | stuck in a busy loop or similar.
         | 
         | And/or possibly take a tea break while it chills out.
        
         | embedding-shape wrote:
         | > but what are you able to do about it?
         | 
         | Depends on the environment, back when I had a MacBook, they
         | still had fans, but the new ones are all passive, I think. So
         | then the surface (or lack of it) below it would matter the
         | most. If you keep it in your lap, on top of a hairy blanket,
         | it'll be a lot effective at getting rid of the heat compared to
         | if you have it sitting on a stone table, as just one example.
         | 
         | Edit: Seemingly the split of Air/Pro being passively/actively
         | cooled seems to still apply today, so then checking fans, their
         | performance and intakes/outtakes for _chaff_ tends to be the
         | best way, if you have a Pro.
        
           | saagarjha wrote:
           | MacBook Air is passive, MacBook Pro is not
        
           | hu3 wrote:
           | New macbooks still have fans. Depending on the model.
        
         | vunderba wrote:
         | I've been using Macs-Fan-Control since I picked up a Mac M1 a
         | few years back and it works great. It lets you control the fan
         | RPM based on CPU Core values.
         | 
         | I adjusted it to ramp the fans up at more conservative values
         | because otherwise during intense usage periods it would hit
         | 90C+.
         | 
         | https://github.com/crystalidea/macs-fan-control
        
         | giancarlostoro wrote:
         | I use TG Pro on my Macbook Pro to auto-cool my Mac. It drives
         | me crazy that Apple lets your Mac burn to a crisp before
         | kicking on the fans.
        
           | varenc wrote:
           | Is Apple actually letting the Mac burn to the point at which
           | it has damage or other negative consequences? I've definitely
           | observed they delay the fans until they're absolutely needed,
           | but I trust their thermal management to not actually cause
           | harm. (besides a warm lap)
        
             | giancarlostoro wrote:
             | I'm not sure, but I know I'm not the only one who is
             | concerned about how hot it can get long before the OS kicks
             | on the fans.
             | 
             | https://www.reddit.com/r/MacOS/comments/1kmacsf/macbook_pro
             | _...
        
       | sys_64738 wrote:
       | brew install stats
        
       | nazgu1 wrote:
       | There is a problem/bug with thermal pressure notifications. Did
       | you stumbled upon such issue with your app?
       | https://github.com/macmade/Hot/issues/73
        
         | angristan wrote:
         | Ah! Yeah I did notice that using
         | `ProcessInfo.processInfo.thermalState`, the state didn't update
         | unless I restarted the process (reproducible even with a swift
         | script). But this issue doesn't happen with the technique I use
         | right now (the thermald notification)
        
           | nazgu1 wrote:
           | Thanks, I will check your approach. And your app as well,
           | looks beautiful and useful.
        
             | angristan wrote:
             | Thank you for the kind words :)
        
       | twilo wrote:
       | You can just ping your CPU usage to the menu bar and monitor
       | that. I have CPU and total system wattage up there so I always
       | know if something weird is going on.
       | 
       | https://github.com/exelban/stats
        
         | angristan wrote:
         | Yeah! That's how I initially suspected that it was thermal
         | throttling because I saw in iStat Menus that my wattage was
         | going down for a constantly high CPU usage
        
       | rkagerer wrote:
       | This would be a really useful thing to indicate via an
       | unobtrusive LED on the chassis somewhere.
        
         | echoangle wrote:
         | Why would you take an LED over something on the screen? The
         | notification is only really relevant while the laptop is open,
         | and the screen is going to be on anyways.
        
         | alexford1987 wrote:
         | There is no way Apple would do this on a MacBook Air, which is
         | able to be passively cooled because of the type of use
         | cases/users it is primarily designed for, most of whom never
         | hit throttling. The light would only confuse almost everyone.
        
       | mschuster91 wrote:
       | Another thing to keep in mind with MacBook Pro models or any
       | other device that has fans... if you have cats, dogs or other
       | heavily shedding animals, you _must_ regularly (for me, once a
       | year, for people with German Shedders more like once a quarter)
       | open them up and thoroughly clean them.
       | 
       | The amount of fur that manages to squeeze _everywhere_ is insane.
        
         | vunderba wrote:
         | Husky/Pyr owner here - I have to systematically blow out all of
         | my electronics because she molts enough fur to start my own
         | Etsy brand of stuffed animals.
         | 
         | The _WORST_ thing, though, is that all her fur makes its way
         | into all my musical instruments, including underneath each
         | individual key of my upright piano (now effectively a felt
         | piano).
        
       | the_black_hand wrote:
       | My 2017 macbook is basically brick. Crazy how just opening chrome
       | sets off fans like a jet engine. How much cpu can checking gmail
       | really use?
       | 
       | Foolish me is considering buying a new macbook this year. I have
       | no choice because Apple and Microsoft will do everything in their
       | power to ship the shittiest personal computing products every
       | year.
        
         | lanyard-textile wrote:
         | The butterfly keyboard of that era was a large enough signal,
         | to me, that high quality engineering results were compromised.
         | 
         | They produced a laptop that you can't type efficiently on??
         | That misses key strokes?! I had to slow my typing on those
         | keyboards!
         | 
         | So, imagine the incredible contempt I have had for Apple for
         | failing such a basic delivery. Still, their new silicon
         | machines managed to turn my opinion around -- quite the 180.
         | The speed improvement is genuinely remarkable, and the modern
         | build quality otherwise seems excellent to me.
         | 
         | It's worth another try imo.
        
         | Arn_Thor wrote:
         | I'm sorry you're saddled with an Intel Mac. The Apple Silicon
         | Macs really changed everything. Clearly Apple is capable and
         | willing of shipping extremely good and performant hardware,
         | even though historically they haven't always done so. I do
         | blame Intel for their monopoly on mediocraty for the late-10s
         | Macbooks though.
        
           | bigyabai wrote:
           | Now put Linux on it. Just like new!
        
         | throwaway270925 wrote:
         | Yeah, 2016-2019 were severely cooling constrained
         | unfortunately.
         | 
         | If you want to keep using it (maybe not as your main machine)
         | there are some workarounds and fixes:
         | 
         | The simple software only way is to deactivate Turbo and/or HT.
         | Less performance but also less power use meaning less heat. And
         | checking gmail or browsing the web you probably wont notice
         | much of a difference.
         | 
         | Or you can open it up and add thermal pads to your VRMs,
         | finally giving them adequate cooling. Just dont touch the
         | bottom of your macbook afterwards or rest it on your bed or
         | couch, that thing can get hot!
        
         | dplgk wrote:
         | I recommend taking the bottom panel off and cleaning out dust
         | from the fans and air ports
        
       | marksomnian wrote:
       | Site appears to be hugged to death, repo is:
       | https://github.com/angristan/MacThrottle
        
         | angristan wrote:
         | Oops, I fixed it, I have not very important Cloudflare Workers
         | in front of the blog (which is on Cloudflare Pages) and somehow
         | they were in fail closed mode and not fail open :(
        
           | brikym wrote:
           | I have had back luck with them intermittently losing routing.
           | Sometimes re-creating the worker fixes weird issues.
        
             | angristan wrote:
             | This one is my bad, I've exceeded the 100k free reqs/day
             | (for https://stanislas.blog/2025/02/redirect-dead-links-
             | hugo-imag...), and I didn't enable the setting to bypass it
             | over that limit
        
       | edwardtay wrote:
       | Nice work! This is a practical tool that fills a real gap. A few
       | thoughts:
       | 
       | 1. Have you considered adding historical tracking/graphing? Being
       | able to see throttling patterns over time would be super valuable
       | for understanding workload impacts and diagnosing thermal issues.
       | 
       | 2. What metrics are you pulling to detect throttling? CPU
       | frequency scaling, temperature sensors via IOKit, or something
       | else? Would be interested in the technical details.
       | 
       | 3. Integration with menu bar apps like iStat Menus or Stats could
       | be useful - or even just exporting metrics to a format they can
       | consume.
       | 
       | 4. For M-series chips, have you noticed different throttling
       | behavior compared to Intel Macs? The efficiency/performance core
       | split makes this more complex.
       | 
       | 5. Any plans to add alerts/notifications when throttling occurs?
       | Or maybe even automated actions (like pausing backup processes
       | when thermal throttling is detected)?
       | 
       | One use case: this would be great for developers running heavy
       | builds or ML training. Knowing when your machine is throttling
       | helps decide whether to optimize code, get better cooling, or
       | just wait it out.
        
         | widhhddok wrote:
         | The account that posted this comment seems to be a bot account
         | - and one that doesn't even read the article in it's context.
        
           | ChadNauseam wrote:
           | One thing that annoys me about LLMs is how they say stuff
           | that's dumb but sounds smart. For example:
           | 
           | > Have you considered adding historical tracking/graphing?
           | Being able to see throttling patterns over time would be
           | super valuable for understanding workload impacts and
           | diagnosing thermal issues
           | 
           | Would it actually though? Is anyone going to ever check if
           | their laptop was throttling at 6pm yesterday evening and then
           | remember what they were found at that time and try to
           | "understand workload impacts"? It's the type of thing that
           | might come in kinda useful once in a while, not "super
           | valuable". Idk, I notice this trend with LLMs a lot. Often
           | what they say just doesn't really make sense when you think
           | about it.
        
           | angristan wrote:
           | Agreed, half of these questions are answered in the post.
           | Also, looking at the account's comment history confirms that
           | it's karma-farming with comments or something like that
        
       | carterschonwald wrote:
       | Mac fan control seems to track component temps which is pretty
       | nice
        
       | e40 wrote:
       | He could get notarization and code signing for free if he puts it
       | into Homebrew. I would love to get it via that distribution
       | mechanism.
        
         | angristan wrote:
         | Oh really? TIL, I thought it was dependant on the app
         | developer. I can look into it, thanks!
        
         | xenonite wrote:
         | This is great to hear.
         | 
         | Is there a similar free way for getting Windows signatures?
        
       | luxuryballs wrote:
       | This is the type of software you hope Apple will "Sherlock" and
       | bake into the OS!
        
       | gigatexal wrote:
       | neat! got it installed. thank you.
       | 
       | you could easily put this in the App Store (maybe?) and I'd have
       | thrown a few bucks your way.
        
       | tombert wrote:
       | I had the 2019 Macbook Pro i9, so I think a function to determine
       | thermal throttling could be written very simply:
       | function isThermalThrottling() {             return true;
       | }
       | 
       | Seriously, I loved that computer for the most part but I was a
       | little annoyed that I paid a lot of money for the i9 CPU just to
       | get worse performance than the i7.
        
         | merb wrote:
         | I had that problem as well. Especially when connected to two
         | external monitors. I did not love the machine and the M1 Max
         | was such a big upgrade because of that and I could upgrade to
         | the m3 max later and give my m1 to somebody else. Both apple
         | silicon machines are going strong for a long time I guess.
        
         | LoganDark wrote:
         | I had a Mid-2015 MacBook Pro with an i7 and I still ran the
         | fans at full speed at all times (actually above full speed). I
         | had a couple fan failures due to that, but otherwise I think it
         | was worth it.
        
           | j45 wrote:
           | 2014-15 were among the best macbooks ever made. All laptops
           | fail eventually from pushing them extremely hard.
        
         | lbourdages wrote:
         | I had that laptop and it is the worst computer I have ever
         | owned. As soon as you booted the fans would start spinning.
         | There were sometimes kernel panics when plugging or unplugging
         | Thunderbolt devices.
         | 
         | I have an M1 Max MBP now and it has been absolutely perfect.
        
           | thedougd wrote:
           | Same! Still have it as a side machine.
           | 
           | My favorite and most painful issue was a bug in USB charging.
           | Sometimes it would fail to charge from my monitor (USB-C) yet
           | it would believe it's connected. The battery would eventually
           | run to zero and the machine would shutoff without warning. No
           | low battery warning would be shown because it believed it was
           | charging however it was not. Resolved with my M3.
           | 
           | Also fun with that generation is that you can't plug in a
           | dead laptop and start using it right away. Takes about ten
           | minutes of charging before you can power it on.
           | 
           | Also fun, it would not establish power delivery with my
           | monitor in this state. I'd have to plug it in with a regular
           | charger to bootstrap it. Also resolved with my M3.
           | 
           | Now that it's aged, the super capacitor for the clock no
           | longer holds charge and the time is usually wrong on cold
           | boot. I wish that was serviceable.
        
             | tombert wrote:
             | I had heard of the super capacity issue, and while mine had
             | not shown any symptoms of that I decided to sell it before
             | it did.
        
           | tombert wrote:
           | The laptop it was replacing was a terrible Asus computer that
           | literally started falling apart and delaminating after about
           | six months. It felt like it would break a bit more every time
           | I touched it. Asus themselves was wholly unwilling to do
           | anything about it, and they acted like I had been juggling
           | with the damn thing when all it ever did was live on my desk
           | or next to my bed.
           | 
           | It was the third Asus computer I had owned that broke way
           | earlier than it had any right to, and I swore a blood oath
           | that I will not buy another Asus product.
           | 
           | Point is, considering how terrible that laptop was, "annoying
           | thermal throttling" was still a considerable upgrade, so I
           | loved it in spite of it.
        
         | scarecrowbob wrote:
         | I am writing this comment from a 2019 i9. I have to charge it
         | from the right hand ports. I think that is dumb, but it did
         | solve the issue. I have no idea how I came to that conclusion
         | (i almost certainly read about it somewhere), but there were
         | certainly a couple of weeks where it was driving me crazy.
         | 
         | A dumb thing for sure. I still like macos better than windows
         | and I'm heavily invested in a production workflow with logic.
         | Moving to linux would be my next move, but after making that
         | dumb change it's quite a functional machine.
        
           | auscompgeek wrote:
           | It was definitely a relatively well known problem with the
           | 2019 MBP on the internet at some point. I found a Reddit
           | thread linking to a news article about this. https://www.redd
           | it.com/r/mac/comments/vi3grj/you_should_char...
           | 
           | It was so much of a problem that at work we added a check
           | that you were charging from the right ports to our internal
           | doctor script (think like `brew doctor`).
        
           | tombert wrote:
           | FWIW, I replaced that MacBook with a Thinkpad (AMD Edition)
           | about a year, and i have been extremely with it. Not only was
           | it one of the easiest Linux installs I have ever had, but the
           | hardware feels solid, the keyboard (while not one of the
           | legendary classic Thinkpad keyboards) is nice to type on, the
           | 4K screen looks nice, and everything just feels well built
           | and snappy.
           | 
           | Outside of the terrible speakers, it is a nearly perfect
           | computer. I don't really mind a crappy speaker on a laptop
           | since it usually lives on mute and when I need decent-enough
           | quality audio I will plug in headphones or Bluetooth to a
           | speaker, but YMMV.
           | 
           | Still, if this computer ever breaks then I will likely buy
           | another thinkpad.
        
           | j45 wrote:
           | You were not alone.
           | 
           | The epic takedown post of the issue on stackexchange which
           | proved it is below, I ended up at it from somewhere on social
           | I think.
        
         | j45 wrote:
         | There is one pretty epic stackoverflow post that AI searches
         | probably won't find.
         | 
         | It turned out a lot of the thermal throttling (kernel_task
         | usage) on the i9 macbook pros went away if you plugged in the
         | power on the right side, instead of the left.
         | 
         | Why turned out to be a chip (thunderbolt I think) that didn't
         | have enough cooling.
         | 
         | https://apple.stackexchange.com/questions/363337/how-to-find...
         | 
         | One could also put quiet cabinet fans under the i9 Macbook Pro
         | to make it draw air away and run markedly faster. [1]
         | 
         | That, combined with the keyboard failures, meant I could put a
         | wireless keyboard on top of the laptop keyboard and use it,
         | with fans underneath.
         | 
         | This is how I took it to the Apple store for warranty repair,
         | which made a point of it having a pretty massive design flaw.
         | 
         | I asked them this if it was a feature of all macbooks when you
         | buy the fastest ones to have to cool it the right way and not
         | use the keyboard in case there might be dust in the air. The
         | laptop was way too overspecced.
         | 
         | The i9 laptops were made far too thin to cool themselves
         | appropriately in any situation, full stop.
         | 
         | All to say, if I could detect which USB-C port was pulling
         | power in, on those laptops, I could guess pretty accurately
         | what will happen on that i9.
         | 
         | It's sad to know the M4 Max Macbook Pro has the same issue,
         | even though the laptop is thicker. Doesn't make me want to
         | upgrade anymore.
         | 
         | [1] https://www.amazon.com/AC-Infinity-MULTIFAN-Receiver-
         | Playsta...
        
       | atymic wrote:
       | Found https://github.com/macmade/Hot which works for my intel mac
       | :)
        
         | tamimio wrote:
         | Thanks for sharing it, will try it now. I found an iMac 2017
         | the other day at the thrift store for $20, it's been very good
         | so far but will see if it throttles or not.
        
       | scottlamb wrote:
       | > I know it's thermal throttling because I can see in iStat Menus
       | that my CPU usage is 100% while the power usage in watts goes
       | down.
       | 
       | There's another possibility. If your battery is low and you've
       | mistakenly plugged it into a low-power USB-C source (phone
       | charger), you will also see 100% CPU usage, low power usage, and
       | terrible performance. Probably not the author's problem, but it's
       | been mine more than once! It might be worth adding something to
       | detect this case, too. You can see your charger power under
       | "System Information"; I assume there's an API for it also.
        
         | angristan wrote:
         | Interesting, yeah iStat Menus reports the wattage of the
         | charger, sometimes I've charged my mac with like a 5 or 10W
         | charger and I didn't have that issue But now that rings a bell,
         | I think a coworker had that issue recently. I wonder why that
         | happens
        
         | hinkley wrote:
         | While I have definitely done this a few times, one of my
         | MacBooks could draw more power than the power supply could
         | deliver and there was a particular computer game that I
         | discovered I could "only" play for about five hours before the
         | laptop shut itself off. Because it was having to draw
         | supplemental power from the batteries to keep up.
         | 
         | IIRC the next generation of MacBook was the one that came with
         | the larger power brick, which didn't at all surprise me after
         | that experience. Then they switched to GaN to bring the brick
         | size back down.
        
         | morning-coffee wrote:
         | > I know it's thermal throttling because I can see in iStat
         | Menus that my CPU usage is 100% while the power usage in watts
         | goes down.
         | 
         | When I read this I wondered "Why isn't core temperature alone
         | not a reliable indicator of thermal throttling?". Isn't that
         | the state variable the thermal controller is directly aiming to
         | regulate by not letting it exceed some threshold?
        
           | angristan wrote:
           | My M4 Max Macbook Pro can run for a while at like 105degC and
           | fans to the max before throttling, when it starts throttling
           | it doesn't exceed that threshold, and then the temperature
           | goes down for a while before throttling stops
        
         | wincy wrote:
         | I have an M1 MacBook Air and do a once weekly virtual D&D
         | session with some friends. I hook it up to my 4K monitor, and I
         | assumed it had to do with that. It kept becoming a slideshow
         | (unless I put an ice pack under it!) and I realized it's
         | because the battery life is so good it's the only time of the
         | week I charge the thing, so charging the battery was making the
         | poor laptop a hot mess that was thermal throttling like crazy.
         | This is with a nice dock that can push around 100W, so it isn't
         | necessarily an underprovisioned charger.
         | 
         | I started charging it an hour or two before our session, and
         | the issues stopped.
        
           | j45 wrote:
           | Try cabinet fans under it, will be life changing.
        
       | tonymet wrote:
       | I hope this great tutorial encourages more developers to build
       | native apps. Still the best development and consumer experience .
        
       | Bad_Initialism wrote:
       | It won't run on a MacBook Air M1 running Sonoma. Only Tahoe.
       | 
       | Come along with me! We'll destroy the planet so fast that we'll
       | all be cinders before you know it.
       | 
       | All we have to do is gobble the marketing speak so fast and make
       | everything shiny and new, and we'll all be dead before you can
       | say "Greta Thunberg."
       | 
       | Come die with me for thin and for stylish. Kill the animals with
       | me for "sleek".
       | 
       | Die. With. Me. Now! I made an app!
        
         | angristan wrote:
         | I merged https://github.com/angristan/MacThrottle/pull/2 to
         | make it work on macOS 15. macOS 14 probably works, feel free to
         | try it out and open a PR to lower the required version if it's
         | the case
        
       | ksec wrote:
       | I really wish Apple uses Vapour Chamber cooling for next MacBook
       | Air M5.
       | 
       | On my MacBook Pro, I have come to the conclusion that Apple
       | priorities low noise level over heat dissipation. And I have my
       | Mac fan control to have a _minimum_ fan speed.
        
       | motoboi wrote:
       | Hypothesis: it's not the CPU, it's the USB controller saturating
       | the thermal mass.
       | 
       | So instead of the CPU or GPU going bonkers, the body gets too hot
       | and they lose thermal dissipation capacity for the normal usage
       | and then overheat and then throttle. They go 100% on the graphs
       | because the throttling reduces frequencies and then load becomes
       | too heavy.
       | 
       | Experiment other adapters and monitors.
        
         | scarecrowbob wrote:
         | Switching which side I charge my 2019 mbp i9 effectively solved
         | my throttling issues, so your premise might be correct as I
         | understand it.
        
           | Coeur wrote:
           | That's interesting, could you tell me more? Like which side
           | and port (front/back) was throttling, which side and port was
           | not? Were you using a power supply to charge or was the mbp
           | connected to a display? Did it only throttle during charging
           | or also during while fully charged? Thanks!
        
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