Warm up your MacBook (2019) | Hacker News Reader

Warm up your MacBook (2019)

z3ugma.github.io

137 pointskristianp131 comments

Warming up a 2019-era (Intel) MacBook Pro was never my problem. Quite the opposite. Those machines ran notoriously hot. The later macOS releases, combined with company-mandated crapware, made it worse. Doing an ordinary build or starting a videoconferencing session was enough to cause the fans to run. On a warm day the fans couldn’t shed enough heat and so the system would go into thermal throttling. The OS would occupy a core with a 100% kernel_task that didn’t do any work but which would serve to prevent actual work from being scheduled onto that core. When four or five out of the six cores were occupied by kernel_task, I knew I was in for a bag of hurt (to steal a phrase from Steve Jobs). Responsiveness went completely to hell. The machine became effectively unusable.

After a while my normal procedure was to run with the thing sitting on top of an ice pack. That would let me run a 60-90 minute video conference without troubles.

The only redeeming feature of these machines is that they could emulate old x86 hardware at speed. That allowed me to run old apps on old OSes without having to keep old hardware running.

My Intel MBP would noticeably raise the whole room's temperature, while the fans ran so loud. We had some corporate security software that would occasionally go haywire and lock up 100% of a core until you rebooted. If you got that at the same time as a video call it would become too physically painful to touch any part of the metal body with bare skin.

Maybe the same type. Each time I call the LLM api the fan starts to work and make big noise. The temperature in the room is going up noticeably for 1-2 degrees.

> Each time I call the LLM api the fan starts to work and make big noise

So every time you do HTTP calls? Nothing there should spin up your fans, unless you use an agent with an horribly broken TUI, I've heard there is a few of those out there. But remotely calling LLM APIs really shouldn't be taxing on your local device, something somewhere is wrong/bad if that's what you're seeing.

If the horribly broken TUI you mentioned is OpenCode, I’d say yes. That’s exactly what I am experiencing.

Sure, if that's what you're using, then that's definitively buggy, unless it's doing compilation or something actually using your resources, just making HTTP calls shouldn't be heavy for your computer. Claude Code was mainly what I was thinking about, as it similarly broken, but I'm sure there are more out there as most of them seem vibe-coded at best.

Yes. Whatever *code, the same when they are working. The node.js backend is awful.

Is it a local LLM? Sibling seems to be assuming remote, but I have trouble imagining a TUI that inefficient.

No. Simply the rest api call in opencode tui. I don’t know why maybe the mbp is too old, at least it served 6 years +.

Not counting compilation passes, the rest of OpenCode is trivial enough that it should work on a 1980s PC.

It’s just so weird.

I had Windows and Mac laptops back then, and the HN snobbishness around the superiority of the Mac was genuinely baffling.

My i9 2019 MBP with discrete graphics was probably the worst laptop purchase I ever made. Docking it to an external monitor would enable the GPU, so even when idling it would run the fans and drain the battery.

I’d read cautionary tales about Windows laptops being pulled out of backpacks scorching hot as they failed to shut down. But that happened to my Mac all the time, too.

The M series though is incredible. I can’t imagine buying a Windows laptop now.

The i9 was notorious. Would thermally throttle almost instantly & for any sizeable build job would end up slower than the i7 IIRC.

Intel really made themselves unpopular with Apple during that period.

> Intel really made themselves unpopular with Apple during that period.

Intel just reenacted IBM's history with Apple, particularly the G5 era. That CPU was instantly a no-go for anything mobile. In workstations it was cranked ever higher with very poor power-frequency scaling, needing water cooling for the beastly 200W idle power consumption and close to 1kW full throttle.

That went well so was a perfect role model for Intel's i9.

> Intel really made themselves unpopular with Apple during that period.

You can't tell me that this wasn't known by Apple before shipping the product. Why did they not provide adequate cooling for the CPU?

This was a laptop, so cooling was very constrained. The fans can only be so big & you can only shift so much air in & out of a MacBook.

I presume Apple knew perfectly well but wanted the halo product to sell to those people who will always pay extra for the perceived “top of the line” product. Once Intel branding had created an i9 that was a bigger number than an i7, then Apple was going to sell it.

It was faster than the i7 after all: just not for very long!

My entirely speculative theory is that the poor thermal characteristics of that era of Intel CPUs didn’t really become apparent until quite late in the development process & by that point Apple had probably committed to buying a fair chunk of Intel’s output.

Apple hardware quality on the laptops was bottom tier during the 2016-2019 "butterfly" era. There's no denying.

It was a truly ridiculous idea to put an i9 in any laptop. That generation of i9 is difficult to cool even with liquid cooler systems in big ATX cases.

Just to remind, the mobile + desktop lines are not the same thing even if they both get the same branding.

The top end chip in the 2019 MBP was the i9-9980HK, which had a TDP of 45W.

Would have been reasonable in a chunkier workstation/gaming type of laptop with the kinds of cooling solutions those usually get, it's not something that needed an actual desktop liquid cooling solution to run well.

But obviously the 2019 MBP design/cooling was not up to that task.

Oh yeah, I forgot about the graphics.

I had (and still have) a 4k external monitor. Naturally I wanted the MBP to drive the monitor with a resolution that took advantage of all the pixels. Unfortunately with most monitor settings the GPU power consumption would produce enough heat to run the fans even if the rest of the system was completely idle! If I set the output to full HD the GPU would cool down and the fans would turn off. But full HD on a 4k monitor is a waste.

It was very strange. I could drive the monitor at 4k but with the image upside down, and the power consumption would be low. But flip the image right side up and it would run hot and turn on the fans.

It took a couple weeks of fiddling, but I finally found a combination of refresh rate, resolution, image orientation (right side up!), and cabling that let me drive the monitor at high resolution without running the fans. What a pain.

(I used iStat menus to monitor GPU power consumption. At “good” settings it consumed about 5w. At “bad” settings it would consume 17w. At a bad setting you could immediately see the various temperatures go up and the fans spinning up to compensate.)

How could orientation and cabling affect heat??

I don't know, but I did observe differences in power consumption caused by all sorts of unexpected things.

At some point during all my fiddling with this stuff, I discovered a correlation between GPU power consumption (as indicated by iStat Menus) and fan speed. For example, if I switched to high resolution, the power would increase, and at low resolution, power would decrease. And of course more power means more heat, which causes the fans to run. That kind of made sense: moving more pixels consumes more power.

But I also observed an effect caused by refresh rate. Oddly, I seem to recall 30Hz would cause increased power draw but 60Hz the power draw was reduced. Yes, this seems counterintuitive. Since I didn't have a good model for what caused the increased power draw, I decided to try all combinations of the settings. On a lark I tried inverting the image and it actually affected the power draw! Probably has something to do with the access order of memory, but I don't really know. And indeed it seems odd that running the image upside down actually pulled less power than right side up.

The cabling issue was a bit more complicated. My initial configuration was to run the video through a dock, with the dock's video output going to the monitor. That always resulted in high power draw. Connecting the computer directly to the monitor did have the effect of reducing power draw... but only in certain configurations.

Changing orientation affects which parts of the display processor are used. In general, the low power states on GPUs are very capricious.

eg. from personal experience, on older Nvidia cards (1080 Ti), just adding +1Hz to the refresh rate (or using a slightly higher resolution, or 10-bit color, or no DSC etc. etc.) caused it to never enter low power mode, changing power consumption permanently from 10W -> 50W.

AMD GPUs on even the most modern Linux kernels don't enter low power states properly. If you do change the power profile to do it more often, browsers become a laggy mess.

Those were John Ive era laptops where form ruled function. Poor thermal, less ports, less keys were all features.

Form always ruled function with Jony Ive, but he always had a good eye for the way compromises shook out. During that era, Ive was creatively checked out but Cook kept him on to maintain the stock price.

i decided to do an experiment and try to run an LLM in my old 2013 MBP. i7, 16 gb mem, 1 tb hd.

Installed Linux mint Xfce Edition for lightness, installed ollama, start to test different models. Gemma4 e4b runs perfectly fine, exposed it to the network, connected to it with my current notebook and use vs code codex to start to run inference.

For about 30 minutes of bliss, this setup work at a reasonable speed... then the MBP shut it self down. It was so hot that it trigger the safety mechanism, the fans sounded like the laptop was about to take off.

I though on leaving it on inside the fridge, but then the WIFI wouldn't reach.

On the other hand, my wife saw all this and offer to buy me an M5... the experiment didn't work as intended, but it did work.

Could be in need of a thermal paste refresh etc.?

and redo the thermal paste

On a laptop that old it might be worth opening it up to blow all the dust out with a compressor or air duster. I’ve often found that to work wonders on old MacBook Pros.

The other issue is that unless the battery has been replaced relatively recently its charging efficiency may not be that great and the high load being placed on it might be causing it to get hotter than it would have done when new.

I have personally replaced the battery a couple of times already... but a good clean up is a good idea

Give the fans a really good going over: tend to find loads of dust and fluff hiding inside them.

> On the other hand, my wife saw all this and offer to buy me an M5...

Hold my beer. I'm going to run Qwen on this 3rd-generation iPod... somewhere my partner can see

i can sell you my MBP, but no refunds if it doesn't work

hahaha

For those without spacebar heating?

They broke that workflow in a recent update. Software these days is horrendous

for those wondering: https://xkcd.com/1172/

"This will start 6 threads that each peg your CPU... "

they're doing what to my CPU????

Bend over for big tech!

Fully utilize.

Also, pour one for the death of the analog speedo. Peg the needle, no more!

Now that's a fun microcontroller project idea. An analog dashboard for ram/cpu/whatever. I'm sure it's been done.

Edit: https://sasakaranovic.com/projects/diy-analog-resource-monit...

Warming it up. For the eventual electron app it'll be running.

Guys, it’s a butt secks joke

Oh my opsec is good but buttsec needs improvement.

How big is the risk of condensation when you bring a cold laptop inside?

All their spec sheets say they support up to x% _non-condensing_ humidity, which I’m guessing is about the dew point?

The uncomfortable fact about the mentioned Wisconsin winters is that inside dew point tends to be quite low.

I’ve always been told to let electronics and musical instruments slowly warm up in their case after bringing them inside. Supposedly reduces the chances of condensation forming.

I still use a 2019 MacBook Pro, in 2026 I found the best way to warm it up was to use it daily and not blow the dust out of it for 7 years. After I opened it up and did that it's running a lot cooler.

Looking forward to the follow up: How to Quickly Cool Down Your MacBook

Strap a thermopile and a peltier on that bad boy

Just do the trick in reverse, surely?

  yes no > /dev/null

No you have to get the yesses back out

  cat /dev/null | yes

You might have to load in maybe.so for that to work though.

Unironically, yes.

My M3 Macbook Pro's palm rests get uncomfortably warm during regular IDE use. It doesn't get hot enough to spin up a fan, but it is enough to be distracting.

interesting. for me only the bottom and the top part above the keyboard gets warm during my work. 16inch model. Is yours the 14inch one?

I have the 14 inch and i've never felt it go warm.

I think the real question is what IDE we're talking about.

I am mostly in PHPStorm with several projects open + sometimes I have Xcode and/or Android Studio open as well

Haven't used PHPStorm but I know Android Studio does a lot of stuff in the background so I wouldn't be surprised if other JetBrains IDEs do the same. Although PHP isn't compiled...

There's still indexing, linting and code analysis tools running as well as multiple Docker containers (those are pretty much idle outside of running tests or migrations to be fair) and whatever else it could be doing in the background.

I spend 95% of the time with just PHPStorm and other stuff like the terminal, slack and ticketing open. And the browser of course (safari). Xcode and Android Studio are rarely opened. Mostly when I want to test out something in the apps that isn't on testflight / firebase yet.

14 inch, running primarily IntelliJ IDEA and Firefox. Around 10% CPU use most of the time, with of course the occasional spike for compilation.

It's not hot, but with 22C ambient it is enough of a rise to be annoying.

Slightly quicker way to do this is opening Microsoft Teams.

For years at work I've been just using Cinebench as a hand warmer on various Macbooks.

I always enjoyed using the power brick to warm up

Modern Macbooks have this issue, the other day I realised I had never heard the fans of it run, so I was wondering if they actually worked.

Found a web based benchmark tool that will run your CPU and GPU at 100% each. While temperatures went up to 90 degrees science... still no fans. Ended up installing a different utility to manually set the fan speed to confirm they worked.

I don't know what they did but it's good.

May I introduce you to local LLMs?

Care to share the name of both tools? Cheers

Multithreaded:

  seq 1 20 | xargs -Iqq -n1 -P0 yes >/dev/null

Or something useful, save space, compressing some talk or edu video, just 6 fps is usually enough for slides or code, opus audio can go as low as 32k and still be decent compared to source quality, expect 10-15x size reduction

  ffmpeg -hide_banner -y -i in.mp4 \
    -vf "fps=6,format=yuv420p,scale=960:-2:flags=lanczos" \
    -c:v libx265 -tag:v hvc1 -crf 32 -pix_fmt yuv420p -preset fast \
    -c:a libopus -b:a 82K -application 2048 \
    -c:s mov_text \
    out.mp4

can go more crazy with this soup

  -x265-params "keyint=800:min-keyint=24:scenecut=20:ref=8:bframes=16:b-adapt=2:rc-lookahead=80:rd=4:subme=5:deblock=1,1:aq-mode=3:aq-strength=0.4:psy-rd=0.4:psy-rdoq=1.0:qcomp=0.7:qg-size=64:rect=1:amp=1:strong-intra-smoothing=1:limit-modes=1:limit-tu=4:rdpenalty=2:tu-intra-depth=4:tu-inter-depth=4:me=star:no-allow-non-conformance=1" \

I just need to build our monorepo

I think any next.js project will do the trick

Speaking of cold weather and warming up computers... I've had my fair share of long bicycle commutes during cold winters and I always wondered whether booting up the laptop right after arriving has any effect on the long-term reliability? Like, are there any components which suffer from being activated when they're really cold?

I always leave the laptop untouched for at least 10 minutes when coming in from the cold. Don't know if it helps but it makes me feel better.

I try to leave my laptop untouched for as much as I possibly can. Definitely makes me feel better too.

At the first half of your comment I thought you would suggest using laptop as a back heater during cold weather rides!

The battery might need warmup, but it would have to be significantly below freezing outside to affect it.

Electrolytic capacitors can freeze up but again, you'd need a Yakutia-like environment for it to actually pose a concern.

Lastly I've heard of circuit boards warping from going from really cold to really hot, but those were power components.

It increases the chance of solder cracks, which is one major cause of failure. Thermal cycles in general will do that, however, and home computers are designed to survive a lot of them.

So overall it’s not something I’d worry about.

I'm from California... What is this "cold" you speak of?

The Donner Party begs to differ

Floridian. I thought "frozen lake" was some sort of Intel CPU reference.

You don't know how right you are. I don't think Apple ever tests their hardware outside the CA climate.

“Designed in California, for Californians” was too long.

I think my last Macbook was Wisconsin-locale instead of California. Closing the lid and putting it to sleep actually caused it to heat up (until the battery died).

It had the soul of a PC

Won't work on M processors, (un)fortunately.

Honestly m1 was very cool no matter what workload you threw at it but at this point m4 max does get pretty hot even with just web browsing.

I've definitely had my m1 air get uncomfortably hot to touch - particularly right above the keyboard. (While doing developery things)

Can't say I've ever thought of a word like "developery", but now that I've seen it I like it a lot :-)

https://xkcd.com/1172/

sanest emacs user

There really is an xkcd for everything

TBH there was a shameful period when producers were "reinventing" QWERTY keyboard and had a better idea whether Ctrl key should be present and where it should be located. Remember when Apple removed the Esc key?

I recently installed an app to manually activate the fans on my MacBook Pro M1 Pro as I've never been able to trigger them over the past 4+ years. Just to check whether the fans even work (they do).

You must be using only lame languages like C or Go or Python that aren’t optimized for laptop warming during compilation. Try using a Real Language with a Real Compiler, like C++ or Rust or Swift, and build decent-sized projects using all cores.

(All joking aside, this is why I have a MacBook Pro. Compilation easily hits the Air’s thermal limits and the performance boost on the Pro with its fan is impressive.)

You could also build Chromium from source. It makes my M1 Max's fans sing.

I get them going full blast in 2 minutes from cities skylines.

I left my Mac Studio running at 100% CPU on all cores for 14 hours, and the case ended up noticeably warm to the touch. It is possible!

Try increasing to 10 cores. Works on my m3 pro.

Or just add an ampersand at the end and execute the command 8 times or so:

    yes > /dev/null&

In homeoffice I always work in the nude and the cold metal of my macbook pro hurts my thighs…

Me the same... sometimes I "accidently" switch on the camera during calls and ask people why they're confused.

Alternatively, you could try compiling an Xcode project. That should do the trick as well.

Does this work with M series ? M series is much colder and my fingers hurt <sob>

Running an LLM in the background is the contemporary version of this.

Just run Intel (x86) apps via Rosetta 2 in the background. You’ll feel that classic Intel warmth coming right back.

This is like setting the high idle in winter to get your air pressure up lol

Or you could get a laptop that doesn't have an metal shell, like a thinkpad.

they often have a magnesium bottom shell

Or just leave the machine plugged in and turned on for like 5 minutes while you grab a coffee or have a conversation. It doesn't really take that long to warm up to room temperature. Unless this guy is like biking 15 miles to work in the winter in which case, he is doing Wisconsin wrong, you're supposed to drive to work with a beer to warm you up.

npm install

That's so 2019... Wasn't the JavaScript era the good old times? Nowadays you're not even able to run these glorious LLMs locally...

  while true; do openssl speed ecdsap384 -multi 2; done

Honestly i prefer my macbook frosty

Sir, this is a Wendy's

> openssl speed

Needs 2019 in title, this is Intel MacBooks not Apple Silicon.

I've found that Baldur's Gate 3 will warm up my apple silicon (everyday tasks do not).

Is that running on Rosetta 2? Rosetta 2 does (or did, maybe it's removed now) a fine job running x86 code on Apple Silicon, but boy was it cycle-hungry to do it.

Apple Silicon is not really the simultaneously silent and quiet and cool system it was in the M1 days.

If you get a MacBook Air it will get quite toasty at throttling limits. After all, it has no fan.

MacBook Pro models and Apple computers in general tend to favor quiet operation over keeping the laptop surface cool.

Many PC gaming laptops go out of their way to keep warm air off the keyboard deck with a high willingness to use fan noise to accomplish that since the assumption is that you’re resting your hands on the computer for an extended period and you have headphones on for your game anyway.

I probably should have clarified that I'm on an M1 then (a macbook pro, so there is a fan). I didn't realize the newer ones get warmer.

BG3 is a native game, they dropped x86 support shortly after launch on macOS (or maybe even in beta)

yes only writes y, not the whole word yes

unless you type

      yes yes

Another (more useful) option is to render an animation in Blender, or run a local LLM.

Now do the opposite for the summer! Show me a command line that cools down the machine! ;)

This is now running Cyberpunk or an LLM locally

To be fair, the fundamental problem here is the author's resting of wrists to type.

This applies to any computer, Apple, Windows or Linux. Desktop or laptop.

If your typing on any computer is dependent on you resting your wrists whilst typing then it is indicative of poor typing technique and/or posture.

And ironically the very thing you think you're trying to prevent by resting your wrists (carpel tunnel and/or strain) is likely to be aggravated by over-reliance on wrist wrests due to the added pressure on the wrist.

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