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The Raspberry Pi 4 needs a fan

jeffgeerling.com

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Re: The Raspberry Pi 4 needs a fan

#91

Post by geerlingguy »

timthorn wrote: post #69
NikolaeVarius wrote: post #51

Earlier quoted context omitted.

Last time I checked, a consumer grade CPU has expected lifespan of 20-30 years, so your CPU is still in its young adult years

The rough date you checked will be relevant - as CPUs move to smaller process nodes, they become more susceptible to this type of failure.

And in my experience, it's usually not the CPU itself that has an issue, but some flaky solder joint, or the BGA under a chip, just like in the Xbox 360 'red ring of death' era. With mass-manufactured products, if you got a device from a batch that was a few percentage points out of tolerance, the thermal stress can cause issues more quickly than if you didn't introduce the thermal stress.

Re: The Raspberry Pi 4 needs a fan

#92

Post by geerlingguy »

Marsymars wrote: post #85
arendtio wrote: post #80

I think 'need' is a pretty strong word in this context. 'Could use' would be a better term, as the Pi 4 clearly works without a fan, just not at peak performance for more than a few minutes. For many use-cases, I would prefer some performance reduction over the noise generated by a fan.

Yes, if you're committed to a silent use-case, your options are essentially between a processor that doesn't throttle, or a processor that starts faster, and then eventually throttles to a steady-state matching the non-throttling processor in performance.

Apparently a massive heat sink like the ICE tower (https://www.seeedstudio.com/ICE-Tower-CPU-Cooling-Fan-for-Ra...) can maintain a safe temp even without the fan running... but that also makes the Pi turn into a massive device with no chance of working in a standard case!

Re: The Raspberry Pi 4 needs a fan

#93

Post by geerlingguy »

seanhandley wrote: post #64
cwyers wrote: post #59

Earlier quoted context omitted.

Is this just about how fast the CPU is, or is there some other reason the k8s experience is better now?

I'm sure 4GB memory helps a lot.

This. Even 2GB is a world of difference.

One of the major issues I had was the master (control) node would start getting a little weird sometimes, and it was always due to memory pressure (even if not scheduling pods on the master Pi).

Kubernetes docs _say_ 1 GB is the minimum memory requirement, but 2 or 4 GB is more realistic, because at 1 GB and no swap you have precious little overhead.

Re: The Raspberry Pi 4 needs a fan

#94

Post by Rychard »

whiskers wrote: post #75
whiskers wrote: post #37

Earlier quoted context omitted.

By default it's always on. If you (optionally) install the daemon then it can use the Pi SoC's internal temperature sensor to control dynamically based on need.

@mindcrime - I can't reply to you due to max depth. The current version doesn't, we're having a new, custom, fan made with an RPM feedback line for a future model but it'll be a couple of months yet.

If you click on the time above the post, it'll take you to a page where you can type a reply.

Re: The Raspberry Pi 4 needs a fan

#95

Post by HeWhoLurksLate »

gadgetoid wrote: post #46
seanhandley wrote: post #3

Earlier quoted context omitted.

I tried a heatsink but it didn't really help unless I had a desk fan providing some air flow.

This pretty much lines up with my findings. I popped the pre-installed heat-spreader off and applied a heatsink with noctua thermal paste... basically no difference- step-by-step chaos here: https://twitter.com/Gadgetoid/status/1151442153584910337 Just adding a small fan (trying to avoid blowing our own trumpet too much here) absolutely demolishes the cooling performance of any reasonably-sized heatsink. Presumably t…

   I still wonder what would happen if a full desktop-sized heatsink was coupled to the Pi 4's SOC.
In all likelihood, you'd see diminishing returns as you get bigger, but that would be quite the sight to see.

I've been tempted for a while to build a big case with some sort of mounting standard (maybe a Peek array?) so that I can add whatever hardware I want to it (mostly electronics). This seems like a job for that.

Re: The Raspberry Pi 4 needs a fan

#96

Post by Bootwizard »

vectorEQ wrote: post #35

most components should do fine under these temperatures no? on PC usually VRM's are heat sensitive, but the CPU can take pretty crazy temperatures itself. is the issue similar on PI? What component is at risk at these temperatures? 60-70 seems a little hot for a small device , but is it really TOO hot?

Damaging temperatures are generally between 90-100°C. Throttling can happen at lower temps and those are usually CPU dependent (and cooler dependent). Also CPUs with less cores handle thermal throttling worse as they have less cores to fallback on if one overheats.

Re: The Raspberry Pi 4 needs a fan

#97

Post by bjoli »

husam212 wrote: post #41

What about a bigger heatsink?

That has been tried to great success with the rpi3, so I suspect it will at least make it less prone to throttling.

Edit: I just stacked a bunch of 10sec coins on the processor (without any thermal compound) brought the idle temperature down by 3 degrees C.

Edit2: Put an carbon tablet pipe on it, filled with coins. It is not up to heat yet, but right now it is idling at about 45C. It would probably be better with some fluid in it. I will probably keep this as my cooler.

Edit3: Seriously: I have wonderful thermal numbers. sysbench for 240 seconds, temperature 62C.

This is a rpi4 with a poe hat, so my passive cooling options are limited.

Re: The Raspberry Pi 4 needs a fan

#98

Post by krisrm »

the_angry_angel wrote: post #24
y04nn wrote: post #7

I installed libreelec on my Raspberry Pi 4 the first day I had it. The CPU immediately started (while playing 1080p video) to heat a lot to the point it stalled. Since I haded a motherboard chipset heatsink that I had laying around on the CPU it worked flowlessly. (I keep it without any case)

This was exactly my intended use case - as a gift for relatives - the problem I've had is that I need it enclosed to prevent tiny little fingers from getting hurt/destroying the thing. Tried soak testing it one night and experienced the same thing :/ Currently I'm hoping that I can modify the case this weekend to fulfill my needs. As something intended to be used by kids to learn about computing I do wonder how many…

> As something intended to be used by kids to learn about computing I do wonder how many are going to get hurt fingers from the heat output by accidentally maxing the cpu and/or touching the USB ports, etc.

Sounds like one of the unexpected lessons will be heat dissipation :)

Probably outside of the realm of weekend hacking, but I wonder if something like this would work for you: https://flirc.tv/more/raspberry-pi-4-case

Best of luck!

Re: The Raspberry Pi 4 needs a fan

#99

Post by knd775 »

whiskers wrote: post #37
knd775 wrote: post #34

Earlier quoted context omitted.

Does it have a standalone mode, where it doesn't need to be controlled by software? I'm interested in using it with prebuilt images that wouldn't be able to run the python to control the fan.

By default it's always on. If you (optionally) install the daemon then it can use the Pi SoC's internal temperature sensor to control dynamically based on need.

Great, thanks!

Re: The Raspberry Pi 4 needs a fan

#100

Post by kees99 »

geerlingguy wrote: post #55
kees99 wrote: post #44

Quote: the metal casing helps spread that heat around It does, to a degree. But that is absolutely not what we are seeing in that IR picture. Shiny bare metal is a mirror at the wavelengths that thermal camera uses. So what you see on thermal image where wifi-module shield and CPU are is reflection of ambient (room) where this picture was taken. Try waving your hand around, you'll see it reflecting there too. To meas…

True, I worded it a bit wrong. But the metal case is a huge improvement over the plastic die package on the Pi 3 B and earlier—a heat sink helps a little but you don't yet _need_ one if you use a fan, since the metal is much better at dispersing the heat.

Indeed - there is enough aluminum/copper in the SoC's metal lid and PCB's inner (ground/power) layers, that the whole thing is effectively a 2-3 square-inch heat-sink. Eben himself has been talking about this technique around the time RPi3+ was released.

And your point here is completely understandable too - there is a kinda-heatsink there already. Just add a fan, and we're good.

My point is - seeing a large black hole where SoC goes (color corresponding to +20-ish degrees C by the chart) is utterly confusing, since SoC is the hottest point actually.

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