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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

#71

Post by adrianmonk »

spiderfarmer wrote: post #25
adrianmonk wrote: post #22

> If you run computing hardware at its thermal capacity for long periods of time, this will cause more wear on the parts than if they are run well inside their limits. So I have a moderately increased likelihood of, at some indefinite point in the future, having to spend a whole $35 to replace the Raspberry Pi. I can prevent this by spending extra money (and time) up front. In some cases, it might be worth it. Maybe…

I would accept the shorter lifespan just because of the fan noise. Small and cheap fans are very noticeable in otherwise quiet rooms. I'd hate it.

I hate fan noise too. Sometimes it's necessary, though. But yeah, noise is another trade-off to consider.

Regarding Raspberry Pi specifically, larger, slow-moving fans tend to be quieter than smaller, fast-moving fans. The Pi is compact, so a small fan would be the natural choice.

Re: The Raspberry Pi 4 needs a fan

#72

Post by strainer »

The Pi4 does not need a fan. There is a grand total of 10 watts of heat to dissipate, 15 watts max supply but that includes power sent to peripherals and wifi. A matchbox sized heatspreader which just touches each of the warm components will work assuming a bit of ventilation is arranged to let 40-50C air float away. The heatspreader shouldn't even benefit significantly from being a top conductive alloy - a bit of tin lid will do the job.

Experiences with shifting 200 watts for cpu cooling has people thinking dedicated alloy sinks and fins and fans are appropriate, but this is just 10 watts - it's child's play ;/

Re: The Raspberry Pi 4 needs a fan

#73

Post by kemayo »

On a related note, there's a pending raspberry pi 4 firmware update which apparently makes a _big_ difference to how much heat it's generating:

https://www.pcgamer.com/amp/if-you-bought-a-raspberry-pi-4-g...

Last I saw, it's still causing some issues with performance of USB devices, which is why it's not in general release yet.

Re: The Raspberry Pi 4 needs a fan

#74

Post by magicalhippo »

junaru wrote: post #29
adrianmonk wrote: post #22

> If you run computing hardware at its thermal capacity for long periods of time, this will cause more wear on the parts than if they are run well inside their limits. So I have a moderately increased likelihood of, at some indefinite point in the future, having to spend a whole $35 to replace the Raspberry Pi. I can prevent this by spending extra money (and time) up front. In some cases, it might be worth it. Maybe…

> If you run computing hardware at its thermal capacity for long periods of time, this will cause more wear on the parts than if they are run well inside their limits. How true is this actually? Personal anecdote is an I5-2500K overclocked to 4.6ghz with budget aftermarket cooler (its at 4.6ghz constantly regardless of load). It's been running 24/7 in my desktop since 2011. When will it fail? I see these disclaimers…

> How true is this actually?

There's a nice write-up here[1]. To summarize, using the Arrhenius equation as an approximation, one roughly gets that a 10C increase in operating temperature leads to cutting the expected lifetime in half.

However this is a rough approximation and does not consider various other failure modes, such as those associated with thermal cycling.

It also does not really matter much when significantly below the rated max temps: 2000 years cut in half is still plenty...

The take-away seems to be that operating continuously near the max rated temperature can have a significant effect on expected lifetime. Also extreme thermal cycling is probably not a good idea either.

[1]: https://www.electronics-cooling.com/2017/08/10c-increase-tem...

Re: The Raspberry Pi 4 needs a fan

#75

Post by whiskers »

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.

@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.

Re: The Raspberry Pi 4 needs a fan

#76

Post by bjoli »

seanhandley wrote: post #3
reallydontask wrote: post #2

I'd guess that heatsink and a case with heatpipes would be sufficient for most, though perhaps not all, uses and silent, which for me is pretty important on a Raspberry Pi

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

did you try a big enough heatsink? I put a northbridge heatsink on my odroid xu4, and it did even better than the stock cooler with a small fan.

Re: The Raspberry Pi 4 needs a fan

#77

Post by robocat »

seanhandley wrote: post #56
dbg31415 wrote: post #50

Earlier quoted context omitted.

Over the years I've used Raspberry Pis as little media players, but they kept burning out every 3-4 months; the card reader (their SSD) wouldn't work, or they'd just blink some other error message. I thought they were just cheaply made ($35 after all). Anyway, long story short, I got a fan and the last one has been working for over a year without issues.

SD cards have a limited number of writes so if you have the OS constantly writing to it then eventually it sets itself read-only. You can mitigate this somewhat with https://github.com/azlux/log2ram With some finagling you can get them to boot an OS from an external disk then your SD card can just hold a read-only boot loader.

Heat causes flash memory to fail faster.

I couldn't find a good source that quantifies the effect, but this mentions it: https://www.atpinc.com/blog/ssd-data-retention-temperature-t...

Re: The Raspberry Pi 4 needs a fan

#78

Post by giobox »

AnIdiotOnTheNet wrote: post #30
malensek wrote: post #9

Even the previous-gen Pis would easily throttle under load without a heat sink (although usually installing a decent heat sink was enough to resolve the problem, assuming decent airflow). As the article notes, the heat was mainly from the SoC in the past. The Pi 4 is on a whole different level indeed. I imagine the logic here is the same as with many other Pi accessories: if you need it, you'll buy it or get it as pa…

Yeah, I'm kinda wondering just what the Pi is supposed to be at this point. Is it still an inexpensive low power device for teaching basic computer science? Because it seems like it's more for making Kodi boxes or the worlds most powerful LED blinkers.

I'd love to see some kind of reasonable data on the breakdown of how many Pis actually end up in education environments vs RetroPie/Kodi/PiHole/whatever else "service on an SD card image" turnkey solution type thing people use them for. At this point, my guess/gut feel is that education is an increasingly small part of the market for the Pi, yet appears to still be the main focus of the Pi Foundation.

I've always felt the educational focus was much more about the rose-tinted memories of parents who grew up in the homebrew computing generation in the UK. It feels much more a product for me in that regard than it does my kids. Ebon Upton et al are of this generation as well. British computer people of a certain age love to remember their ZX Spectrums etc.

Re: The Raspberry Pi 4 needs a fan

#79

Post by danaos »

LeonM wrote: post #6

So does the pi 3 if you stick it in a case, even with a heatsink. I was using a pi 3 with a heatsink in the official case to play a h265 movie (which will be software decoded on a pi3). After about 10 minutes I noticed it started dropping frames and it displayed the thermometer symbol in the top-right of the display. When I removed the top lid from the case, the temperature dropped enough for the thermometer icon to…

Well the pi3 does not support h265 acceleration natively, it should have been better to use it on h264 movies.

Re: The Raspberry Pi 4 needs a fan

#80

Post by arendtio »

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.

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