back to article Raspberry Pi burning up? Microsoft's recipe can save it and AI

Microsoft, of all people, has offered a recipe for cooling the Raspberry Pi 3. Redmond's put the Pi to work on some AI-related chores and found the poor wee things run rather hot when working near their peak capacity. As the infrared shots below show, the Pi runs quite cool at first (left) but after a few minutes of exertion …

  1. Anonymous Coward
    Anonymous Coward

    Re. Pi 3

    Yeah, also noticed this "feature".

    I found out that many folks with the 3 just find an old fan from a small set top box or netbook and use that, for my ancient 3G/Wifi sharing Airtel b0xen added thermal pad and heatsink + micro fan stopped it frying.

    Interesting idea. Read the thermal state and then change the sync rate to throttle the fan using the normally unused video output or a spare I/O pin.

    IIRC the Pi can only output video to HDMI or composite not both but sync is generally on when Pi is active.

    LM1881 would work fine in this application as 3/4 pin fan just responds to a pulse width modulated signal.

    As my current projects include running Pi's at "Ludicrous Speed" (tm) this is very handy as it also lets me monitor each unit for failure so it can be rebooted by the MCP.

  2. Voland's right hand Silver badge

    and found the poor wee things run rather hot when working near their peak capacity.

    I noticed that long ago. You can get similar socs that do not get anywhere near that hot at the same load for the same price - Banana Pro comes to mind.

    1. Lysenko

      You're right that an A20 will deliver more MIPS per watt of excess heat, but if you run flat out (as here) it will get just as toasty (the H3 in other models is even more prone to odd thermal effects). That's not a criticism of course. SBCs aren't laptops. Cases, fans, power supplies and other peripherals are in the hands of the user, by design.

    2. ZSn

      Has anyone tried the odroid offerings? The c2 or xu4?

      1. Anonymous Coward
        Anonymous Coward

        I've had several C1's and C2's.

        Great little boards, just a bit more geeky and fiddly to work with than the RPi due to the smaller community.

        Plus side is they have native 1Gb/s ethernet, and 1 or 2 GB of RAM, which is nice.

        My C2's run warm, but I've never felt the need to start bolting fans to them. I guess they're partly helped by having a bigger heatsink than the RPi, and partly by the RAM and CPU being in physically different locations on the board. The RPi, IIRC, is still using their club sandwich approach, with the CPU at the bottom of the pile.

        Unfortunately the main UK distributor of the Odroid range charges exorbitant rates for postage, even going to the extent of applying black marker pen over the postal label to try to hide the <£3 postage after he's charged you over £11. TBH, if it wasn't for that, I'd own more.

        1. drgeoff

          No sandwich

          RPi3 (and RPi2) do not have the "club sandwich". The Broadcom CPU + GPU chip and the RAM chip are on opposite sides of the PCB.

          1. pPPPP

            Re: No sandwich

            I have a few RPI 1s. The only one currently in use runs a slimmed down Slackware install with Pulseaudio, a bluetooth sink and not much else. It's connected to the stereo in the kitchen. I've got an RPI3 with OSMC connected to the TV and it does a great job; it hits 85 degrees on occasion but the effect isn't noticeable.

            I used to have an RPI 1 running as my main server although I've replaced it with an Odroid XU4. The Odroid is brilliant. The RPIs are crippled with their shared USB2 bus and could only managed a few MB/sec throughput from the connected external USB3 drive via the integrated Ethernet port.

            The Odroid on the other hand is constrained only by the limits of the ports. 70 MB/sec is about normal; more than I need.

            It has plenty of CPU too. I run DNSmasq (DHCP, DNS (with adblocking), TFTP and PXE), OpenVPN, NFS, CIFS and NextCloud. And it handles it all with ease. The attached fan rarely comes on.

            I was surprised how easy it was to get the 32-bit Raspberry Pi Slackware build working on it, although the 32-bitness started giving me trouble once I had the need to compile some software. As there's no 64-bit Slackware ARM I ditched it and went with Arch. A doddle to set up and within a few hours I'd migrated.

            The XU4 is expensive compared with the Raspberry Pi but performance is in another league.

      2. Frumious Bandersnatch Silver badge

        Yup. Well, C1 and XU4. The C1/C2 have gbit Ethernet and are faster than the Pi boards. You can also fit emmc (from the same supplier) for faster onboard storage. USB2, like Pi.

        XU4 with "cloudshell" case is very nice. Uses one of the USB3 ports for a SATA bridge so you can put in a laptop drive. The other USB3 is accessible for other uses. The whole thing makes a nice small-form NAS. It's also got a small LCD screen (CGA res) integrated in the case so it can be used as a (tiny) terminal in a pinch, or most likely you'll want to use it for status messages. It has an IR sensor, so you could use remote to turn on the screen and control the box without a keyboard. Also has Gbit Ethernet.

        Horses for courses, I reckon. Pi is cheap and cheerful, but C2 gets you more bang per buck, benchmark-wise. The more expensive Odroid boards are just more grown up with more RAM and faster I/O interconnects. Better for more serious projects/roles.

  3. Mikel

    Pi 3 is fine

    Microsoft is using it wrong, is all. Which isn't surprising.

    For AI related chores we'll want to wait on Google's accelerator SOC.

  4. Steve Davies 3 Silver badge


    Apart from the 'geekness' quotient, the RPi does not (AFAIK) run Windows so what's in it for them other than a wee bit of street cred amongst those who never thought about cooling anything other than their beer.

    1. I3N

      Re: Why?

      Was burned twice on Intel's Galileo ... first when time upon purchase ... maybe too much credit on that beer ....

    2. Voland's right hand Silver badge

      Re: Why?

      I tried using Pi model 3 as a CCTV controller for my summer house. The Model 3 proved completely unusable due to heat issues and Model 2/2+ simply did not have the grunt. Same for a couple of other projects like a DIY time capsule - it overheated when reading/writing from an encrypted HDD every time.

      The issue with the Model 3 is two-fold. It runs very hot at the top frequency and has only two frequencies at any given time with a very long transition time. I think (not sure, but it looks like that) it also transitions the whole CPU, not just one core like all well behaved SoCs if it gets loaded. As a result even if the Pi looks moderately loaded (loadavg ~ 40) it spends 95% at the higher frequency.

      I tried downclocking it, heatsinks, etc - does not help. It just runs way too hot. End of the day, I replaced all Pis which were doing CPU or USB intensive stuff with Bananas and called it a day. While the Banana has issues as well, heat and USB are not one of them

      1. druck Silver badge

        Re: Why?

        @Voland's right hand well if your coding is anything like your comments, no wonder its ending up in ->

        1. wolfetone

          Re: Why?

          @druck & @Voland's Right Hand....

          Lads, why start this when none of us has a popcorn icon?

          1. LaeMing

            Re: Why?

            > @druck & @Voland's Right Hand....


            > Lads, why start this when none of us has a popcorn icon?

            Just put the corn on the Pi chip one at a time until you have popped them all.

      2. Lysenko

        Re: Why?

        Nano Pi A64 is better (and cheaper) for that job in my experience, but if you're doing motion detection (or something similar) then the software you use has more of an impact. Using a multi-core CPU effectively is nontrivial and it is very easy to burn a huge number of cycles (and therefore heat) in busy waits and context switches.

      3. Dan 55 Silver badge

        Re: Why?

        Try a Flirc whole-case heatsink. Seems to work for me.

        1. ZSn

          Re: Why?

          Does the flirc still keep it cool when all four cores are at 100%. I'm running of buying one but they're not cheap

          1. Whiznot

            Re: Why?

            The Flirc case cools the RPi3 dramatically lower than does small passive heatsinks. I never use mine for anything more demanding than playing video with analog audio enabled.

          2. Dan 55 Silver badge

            Re: Why?

            I ran cpuburn (all four cores at 100%) and it maxed out at 82.7°C with an ambient temperature of 23.5°C. Normally when running as a media centre it runs at about 50°C.

      4. Anonymous Coward
        Anonymous Coward

        Re: Why?

        > I tried downclocking it, heatsinks, etc - does not help. It just runs way too hot.

        > End of the day, I replaced all Pis which were doing CPU or USB intensive stuff

        > with Bananas and called it a day.

        ... should have tried a better OS, with better power management.

        1. Voland's right hand Silver badge

          Re: Why?

          should have tried a better OS, with better power management

          The OS does not help. It is with ANY OS.

          The power management on a Razzie is under control of the binary firmware. It is in the depth the 2MB+ of binary blob by Broadcom (so much for any claims of this SoC being open source - as most BCOM stuff actually). You can set max frequency only on boot - it is in the boot config. The SoC depending on the load oscillates between the max and 1/2 of the max which is the "cool" mode.

          This retarded design decision which is 100% inside the very closed and binary part of Raspberry Pi cannot be fixed by ANY OS. At all. It is in the SoC's firmware which is the same for all OS


          If Linux CPU frequency stats are to be believed, it starts spending a significant amount at the higher frequency at 20% CPU load on _ONE_ core and is pretty much constantly at the higher frequency from 50% onwards. From there on there is practically no temperature difference as measured by the internal sensors can load it to 400% (all 4 cores).

          The standard heatsink kit you can get from Adafruit drops the temperature by a couple of degrees, but nowhere near enough to keep the SoC stable under high load. If your ambient temperature is lets say over 25 it dies reproducibly with or without the heatsinks (so the thermal throttle does not work either). Compared to that, I have had Bananas survive under load from -20 to +45 ambient.

    3. Tim Bates

      Re: Why?

      Win 10 IoT Edition can run on the RPi3 as far as I understand. Unless they've killed that off too.

    4. bombastic bob Silver badge

      Re: Why?

      there are win-10-nic versions intended for the maker community. surprise. *yawn*

      I don't think anyone's using them to any significant extent, though. Most maker people seem run Linux, some (like me) run FreeBSD (which will REMAIN 'Poettering Free' FOR-EV-AR), and maybe quite a few use an RTOS.

      Win-10-nic on an RPi. *sigh*. Just because you CAN does not mean you SHOULD.

      1. Richard Plinston

        Re: Why?

        > there are win-10-nic versions

        Just don't expect them to be 'Windows". There is no OS GUI, no command line, no multi-tasking. They can run a single program on boot-up and it must be a UWP if you want any output. Development must be done on a full desktop Win10, run is only on Pi3 (not Pi2 or PiZero).

  5. Anonymous Coward
    Anonymous Coward

    Can't we use ice cubes? They are the perfect size for the cpu.

  6. Kevin McMurtrie Silver badge

    Tape fixes everything

    I use pyrolytic graphite tape for my thermal hacks. A patch of it on a tiny hot SMD will spread the heat out enough for the PCB copper traces to provide cooling.

  7. Pete 2

    Doctor, doctor!

    When I raise my arms above my head and clap, I get this terrible pain in my shoulders.

    Doc: then don't raise your arms above your head and clap.

    The same applies to the Pi. While it might, in theory, have enough power to execute the cycles per second needed for AI implementations, it is not designed for that sort of work. You can supercharge a Reliant Robin to pull a caravan - but nobody would.

    And so, for the Pi: simply don't try to run an AI implementation on it. It clearly isn't up to the job.

    1. ZSn

      Re: Doctor, doctor!

      I think it's more Microsoft than anything. I saw a presentation where they were trying to get a neutral net to work on a cortex M0. A raspberry pi should be no problem

    2. phuzz Silver badge

      Re: Doctor, doctor!

      "You can supercharge a Reliant Robin to pull a caravan - but nobody would."

      You say that, but...

    3. This post has been deleted by its author

  8. werdsmith Silver badge

    Pi community has known about this for a while and have worked around it. MS are very late to this party. It doesn't affect me normally as I just leave them sitting on a bench uncased, no heatsink required and then I don't do the equivalent of driving a car flat out in first gear. It's a 40nm very old tech chip which keeps the price down, I think a small charity based outfit would have to think carefully about the spend required to rework it.

    If I needed a cooling fan then I would use something else or downclock it as so much thermal waste really isn't playing the small, quiet low power game very well. Not banana pi though, shocking software and can also get hot.

    1. Anonymous Coward
      Anonymous Coward

      > Pi community has known about this for a while and have worked around it.

      It is a shame the raspberry pi foundation do not take the issue so seriously

  9. Anonymous Coward

    So let me get this right...

    ...when running at a high load for a sustained period, CPU's get hot and need cooling.

    Glad I read The Reg, my 486DX keeps getting warm and wondered how to fix it.

  10. fedoraman

    Hot Office?

    From the Microsoft article: "Room temperature of about 26 degrees C"

    Wow! Try turning the aircon from "heat" to "cool", you'll be more comfortable. And the hardware will last longer.

    1. kyndair

      Re: Hot Office?

      It is well known that humans operate best (for sustained intellectual pursuits, the human brain gets hot quick) in the 18°C to 22°C range, explains a lot about microsoft code.

      1. bombastic bob Silver badge

        Re: Hot Office?

        they're being "environmentally friendly" by making their employees SWEAT instead of running the A/C. didn't you know?

    2. Kevin McMurtrie Silver badge

      Re: Hot Office?

      That's California room temperature. Techies spend less on clothes and office AC.

  11. Anonymous Custard Silver badge

    Flirc case

    The best solution I've found for this is the Flirc case. It's made of aluminium, and has a pillar which comes down directly onto the top of the SoC and connects to it via a pad. Hence the whole case is a massive heat sink, and works beautifully.

    Had the heat problems with my Pi3 running LibreElec (Kodi) when doing more demanding media files, and putting it into that case cured them immediately. Before I saw frequent temperature warnings, since going into it a few months back not one has appeared.

    Of course that exact case design may not work for bolting onto the touchscreen etc, but something of a similar concept with a suitable design should work fine.

    1. Whitter

      Re: Flirc case

      Its likely no longer made, but the Hush case was simply beautiful.

  12. DropBear

    Just try using that stupid "power sipping" this time. I dare you...

  13. Anonymous Coward
    Anonymous Coward

    My Christmas wish, a die shrink to 10nm (or there abouts) for the Pi 4

    1. Bob Vistakin

      Plus 4G onboard flash. Pis can't be used at present for a real IoT applications - SD cards die very quickly under such sustained loads.

      Plus an optimised new Android Things release: 5.1 is a step backwards in terms of performance. Not nice, but understandable - Android 8 Oreo, which it's based on, was a gigantic platform shift...

      1. LaeMing

        I believe the limit on RAM is the Vidcore IV module, which has a hard-coded 1G address range. I would assume if Vidcore V ever ends up in a future Pi, more RAM would become possible.

  14. Dr Doofenburger

    Clicking the link at the top of the page for the tutorial: Active Cooling your Raspberry Pi 3.

    Gives a 404 error. Maybe the hosting server over heated?

  15. Dr Doofenburger

    What you really want is...

    Peltier unit for the RP3.

    1. ZSn

      Re: What you really want is...

      Peltiers are unreliable and the heat so has to be dumped somewhere

      1. bombastic bob Silver badge

        Re: What you really want is...

        "Peltiers are unreliable"

        since when? (unless the device you chose lacks the thermal conductivity you need...)

        "and the heat [snip] has to be dumped somewhere"

        yes, you put a heat sink on the hot side to dissipate it. And?

        1. ZSn

          Re: What you really want is...

          I've had a peltier literally disentegrate on me. Admittedly it was twenty years ago and it was a more substantial one that the one you showed. However they aren't used in any mission critical environments for a reason. In addition while they are good pumps they also are not that efficient and only add to heat that needs to be dissipated (try holding one between you fingers and turn in on - one side freezes to the skin and the other finger is blistered by the heat).

      2. rsole

        Re: What you really want is...

        I really have to take issue with the Peltier coolers being unreliable statement; they are used extensively for Astrophotography cameras where they cool the sensor to -40 to -80 below ambient and they are accurate and very reliable, I have rarely heard of one failing.

      3. Swarthy

        Re: What you really want is...

        "... the heat so has to be dumped somewhere"
        Simple: just bolt a sterling engine on the hot side, use it to spin a dynamo, and feed that into help power the Pi.

  16. This post has been deleted by its author

    1. The Indomitable Gall

      Re: "a fan mount that positions a small blower"

      " Also, that's too hot for a good fried egg. "

      Erm... no.

      The 67 degrees C mentioned on the Guardian article is for sous-vide cooking, and it takes aaaaaaaaaaaages. Sous-vide is a deliberately low-temperature cooking style. I imagine most people actually frying their eggs will be using a notably higher temperature.

      (I suspect most folk would say I fry my eggs at too high a temperature anyway...)

      1. Anonymous Coward
        Anonymous Coward

        Re: "a fan mount that positions a small blower"

        Let's hope the Pi 4 has the option to cook bacon.

        1. The Indomitable Gall

          Re: "a fan mount that positions a small blower"

          I wish people would stop talking about bacon. I'm living in a country where it's not illegal to eat pork products, but as most of the country doesn't, almost nowhere sells bacon. Certainly nowhere in my town. :-(

          Although that said, what I'm missing most at the moment is a toaster and sliced pan bread.

  17. Bob Vistakin

    Microsoft's compute intensive AI task

    Keeping track of incoming security reports?

    Calculating the loss of revenue following it's mobile exit?

    Searching for a market segment it can't royally screw up in?

    1. Dan 55 Silver badge

      Re: Microsoft's compute intensive AI task

      Finding excuses to drop the words "AI", "Windows", and "Raspberry Pi" in blog posts since Google announced a partnership with the RPi Foundation in May.

    2. Flocke Kroes Silver badge

      Re: Microsoft's compute intensive AI task

      Security reports: Just clocked /dev/null at 3GB/s on a Pi3.

      Loss of revenue: Last time I checked, Windows Phone OS had a license fee of $0, but Microsoft is still in the mobile business. They get more revenue patent trolling Android than the wasted on Windows Phone.

      Market segment: Depends ... based on revenue Microsoft has some outstanding successes. Based on customer satisfaction they have some craptacular failures. How about:

      [ 0 == $(($RANDOM%2)) ] && echo Copy Apple || echo Copy Google

  18. Milton

    What story?

    RPi can get hot when maxed. A fan + heatsink combo sorts it. Latter can be bought, integrated into a case that positions it just right, for a few quid on Amazon. Well, duh.

    Is this a "news story" because Microsoft just discovered what the rest of have known for years?

    I'm beginning to wonder if an entire category of "news" was invented about 10 years ago, in which something utterly pedestrian and already in wide use is hyped and ballyhooed as soon as MS or Apple "invent" it again.

    If the internet's infinite supply of column inches simply *has* to be filled, may I suggest you deploy clickbait headlines (which El Reg can practise its signature sophomoric puns upon) followed by a stream of random gibberish and a bad photo of a cat?

    After all, the headline "You'll Never Believe 5 Ways Microsoft Are Idiots" doesn't actually need any follow-on content, does it?

    1. Captain DaFt

      Re: What story?

      After all, the headline "You'll Never Believe 5 Ways Microsoft Are Idiots" doesn't actually need any follow-on content, does it?

      HA! Nobody on the IT coalface will ever fall for that headline!

      Five is waaay too low a number!

  19. This post has been deleted by its author

  20. jppx

    ASUS Tinkerboard

    When I need more grunt than the RPi3 can deliver I use an ASUS Tinkerboard. Sure it's more expensive and requires a heatsink/fan anyway. But its about 1.5x faster.

  21. Tom 7 Silver badge

    If its not used in a mobile application

    a piece of copper pipe with the end cut and bent over (but leaving holes for air to pass) can be used as an admirable heat sink. Thermal paste sort of sticks it down. Takes a couple of minutes to cut out with dremmel

    1. LaeMing

      Re: If its not used in a mobile application

      Or a small copper cube bridging the top of the chip to a square-foot of aluminium ex-BBQ grille!

      1. Tom 7 Silver badge

        Re: If its not used in a mobile application

        Not seen easily available small copper cubes! A piece of 9mm copper pipe about 6" long seems to keep the CPU cool at full non-accelerated blast. I made a vertical cut in the pipe and then out to the edge so the remaining tongue was just big enough to cover the cpu when flattened out and then bent 90 degrees across the remaining pipe so there was a bit of an air gap and put a couple of solder dots to help heat transfer. The chimney effect works quite well but if I was to do it again I'd drill 3mm holes to cut out the waste so there are more air holes and also copper to conduct the heat to the chimney.

  22. Dave 32


    Ok, so where's the picture of the obligatory geek who's cooled one with Liquid Nitrogen? Or, Liquid Helium for bonus points?


    P.S. Hey, don't use all of the Liquid Nitrogen for cooling the chip; I need a bit of it for cooling my beer.

    P.P.S. Sorry, I'm an American. We like our beer cold, as opposed to other parts of the world.

    1. Flocke Kroes Silver badge

      Re: Cooling

      Here is the liquid nitrogen.

    2. The Indomitable Gall

      Re: Cooling

      The most ridiculous one I've seen yet is the geek who suspended his Pi in a small fishtank full of mineral oil. With that much oil, he didn't even see the need to include a circulator, which is fair enough as convection should probably handle it.

  23. Doctor Syntax Silver badge

    A new application: frying quails' eggs in high end restaurants. As a bonus the temperature can be controlled by the software.

  24. Sorry that handle is already taken. Silver badge

    "Egg frying"?!

    Have you tried to "fry" an egg at just 85°C?

    1. Tom 7 Silver badge

      Re: "Egg frying"?!

      You can boil them at that temp so frying would probably work but with no sizzling at sea level.

  25. This post has been deleted by a moderator

  26. This post has been deleted by its author

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