The Raspberry Pi 4 needs a fan • Hacker News Board

Re: The Raspberry Pi 4 needs a fan

#171

Post by LeonM » Wed, Jul 17, 2019, 6:40 PM UTC

danaos wrote: post #79

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.

That is correct. A pi 4 can doe h265 acceleration, but for anything other than a pi 4, use h264 content.

Re: The Raspberry Pi 4 needs a fan

#172

Post by nullbyte » Wed, Jul 17, 2019, 6:41 PM UTC

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…

I'm hosting a Node.js webserver from my RPi3, I have heatsinks and a case installed with no fan.

Seems to run fine, it's never overheated or throttled for me.

Re: The Raspberry Pi 4 needs a fan

#173

Post by stan_rogers » Wed, Jul 17, 2019, 6:41 PM UTC

godelski wrote: post #163

delinka wrote: post #103

Earlier quoted context omitted.

Why would the overlay need to be with the board that had a coating? Buy two boards, cover the parts on one board that are silver, shoot IR. Use second board for visible wavelength photo, combine for a beautiful overlay result.

Why would you assume that they are different boards?

It's not an assumption, it's a suggestion for making an thermal/visible light overlay photo where the IR photo shows only emitted light.

Re: The Raspberry Pi 4 needs a fan

#174

Post by prashnts » Wed, Jul 17, 2019, 6:41 PM UTC

I’ve been using old ssd cases (aluminium ones), which would otherwise end up in trash. Drill four holes, use a screw to create threads in those holes. Lay some thermal tape, and mount the pi. I haven’t seen it rise above 60degs — plus it looks alright in my opinion. Few pictures here [1].

I got rid of the ports because I don’t need them (headless) and so they mostly fit entirely. I’ll make some sorta cover though.

Edit: Forgot to mention that these cases are strong. It fell a few times and nothing visibly bad. I added Pimoroni shim in second iteration because I did want to keep hdmi there. Also left the Ethernet leds for indicator lights.

https://imgur.com/a/5DdWQ68

Re: The Raspberry Pi 4 needs a fan

#175

Post by superkuh » Wed, Jul 17, 2019, 6:43 PM UTC

This is also true for any real computer which isn't a desktop or server. Smart phones, SBC, whatever, they all have form factors which mean they can't disipate heat easily. They all thermally throttle quickly.

Re: The Raspberry Pi 4 needs a fan

#176

Post by penagwin » Wed, Jul 17, 2019, 6:48 PM UTC

prashnts wrote: post #174

I’ve been using old ssd cases (aluminium ones), which would otherwise end up in trash. Drill four holes, use a screw to create threads in those holes. Lay some thermal tape, and mount the pi. I haven’t seen it rise above 60degs — plus it looks alright in my opinion. Few pictures here [1]. I got rid of the ports because I don’t need them (headless) and so they mostly fit entirely. I’ll make some sorta cover though. Ed…

I have over 4 RPi's and many SSDs and I've never thought of that, nice!

Re: The Raspberry Pi 4 needs a fan

#177

Post by pwg » Wed, Jul 17, 2019, 6:48 PM UTC

prashnts wrote: post #174

I’ve been using old ssd cases (aluminium ones), which would otherwise end up in trash. Drill four holes, use a screw to create threads in those holes. Lay some thermal tape, and mount the pi. I haven’t seen it rise above 60degs — plus it looks alright in my opinion. Few pictures here [1]. I got rid of the ports because I don’t need them (headless) and so they mostly fit entirely. I’ll make some sorta cover though. Ed…

> use a screw to create threads in those holes

You'll get better quality threads, and it will likely be easier, if you use a proper tap to create the threads: https://en.wikipedia.org/wiki/Tap_and_die

Re: The Raspberry Pi 4 needs a fan

#178

Post by NightlyDev » Wed, Jul 17, 2019, 6:49 PM UTC

blackflame7000 wrote: post #126

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.

Also if you are not using a good power supply the Pi will happily operate on less current except when it needs that current during power-intensive operations like watching a movie. This could be causing silent corruption as it happened in my case. If you ever see a thunderbolt symbol best check your power supply.

What are you guys using since you're talking about symbols?

Re: The Raspberry Pi 4 needs a fan

#179

Post by simongr3dal » Wed, Jul 17, 2019, 6:54 PM UTC

guelo wrote: post #155

ryanmercer wrote: post #148

Earlier quoted context omitted.

To add to this, I wonder if a properly designed case could create a chimney effect (not unlike the crossdraft kiln Primitive Tech made in his most recent video) where escape heat is drawing in cooler air in such a fashion as to be adequate enough fo the vast majority of applications. Not that fans need to be very loud, or even spin very fast for something of this size, I imagine relatively low RPMs (probably sub 100…

But then you would need a "This Side Up ↑" label and you would only be able to orient the case in one way.

The case has small rubber feet on one side and the case is slightly dome shaped on the other, I think people will be able to place it correctly without an explicit instruction, plus there is only one “right way” to place it as it is already.

Re: The Raspberry Pi 4 needs a fan

#180

Post by outworlder » Wed, Jul 17, 2019, 6:56 PM UTC

book-mind wrote: post #62

gadgetoid wrote: post #52

Earlier quoted context omitted.

There's a better image here- https://medium.com/@ghalfacree/benchmarking-the-raspberry-pi...

That image is still highly misleading, you can see from the overlayed optical image that the CPU is not coated. Ideally you'd want to coat any metal surface with black epoxy, and set the IR camera Emissivity Coefficient to 0.9 (the coefficient for black epoxy).

Wouldn't that change the heat dissipation characteristics and skew the results? Is a metal surface coated with epoxy exactly the same (from transmission, convection and radiation point of views) as a naked metal surface?