Way to keep your cool running a Raspberry Pi 4 (2019) • Hacker News Board

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#71

Post by ja27 » Wed, Jun 10, 2020, 4:13 PM UTC

smichel17 wrote: post #57

Arnt wrote: post #24

Earlier quoted context omitted.

Would you describe that flirc case as complicated? To a naïve layman, it seems like the smallest all-metal case that'll fit the rpi4, made so that the metal acts as a heatsink. Which may be more heatsink area than a 15W CPU needs, but not bigger case area than is needed. Is there something I'm missing?

I got a pi 4 around 6 months ago and got the flirc case based on the recommendation of TFA. I've been very pleased with it - makes the pi look nice; I no longer worry about other people touching it; and of course it cools well (the very thick thermal pad connecting to the case is a bit unusual, but it works). I got the flirc usb dongle for remotes at the same time, since I thought I'd want it (my pi is a media center…

Kinda wish the top of the FLIRC case wasn't rubberized. My older one is sticky now, but that might be more of an issue in Florida humidity. Still got one for a Pi 4 and it ran well enough.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#72

Post by hajile » Wed, Jun 10, 2020, 4:15 PM UTC

vardump wrote: post #42

The article is dated November 22, 2019, which makes me wonder whether it was before the Raspberry Pi 4 firmware upgrade that reduced heat generation quite a bit. My two 4GB Raspberry Pi 4s have had no thermal issues. Running the same measurement script now, will report back the results. Edit: Ok, done with the tests. Both RPi4s are bare and should be running exactly the same versions. RPi4 #1 started at 51C, peak 79C…

TDP theoretically scales linearly with clockspeed and scales worse in reality. Most Pi 4 can sustain 2.1GHz CPU and 650-750MHz GPU. That's a 30-35% increase in clockspeeds. If I'm taxing the system, even a FLIRC case will throttle on my pi. ICE tower has done an amazing job and the sound isn't noticeable on 3.3 volts. In fact, you can simply unplug the fan and passively cool (though it'll throttle after a few minutes at peak clocks).

I used the pi for dev work for a few weeks as an experiment. Overclocking is the single-biggest improvement you can make. An overclock combined with the IPC improvements from a 64-bit OS, and load improvements via SSD, the system is probably 75% faster which is a huge deal at that performance level (the difference between extremely frustrating and just mildly annoying at times).

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#73

Post by hajile » Wed, Jun 10, 2020, 4:23 PM UTC

rc4hobby wrote: post #21

Thermal engineer here. There absolutely no need to use fan cooling, humongous heatsinks or harebrained temperature controller schemes to cool the raspberry pi 4. All that is needed is a small heatsink to slightly decrease the thermal resistance to ambient air, to stay below the thermal throttling threshold. Anything more complicated than that is a pointless exercise in pointlessness.

Somebody's never overclocked their pi before...

With an overclock, even a FLIRC would throttle when running our full unit test suite. A 30% reduction in unit test runtime is nothing to sneeze at and I certainly didn't want to downclock to 600-800MHz due to throttling. An ICE Tower was a lifesaver.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#74

Post by Havoc » Wed, Jun 10, 2020, 7:00 PM UTC

vardump wrote: post #42

The article is dated November 22, 2019, which makes me wonder whether it was before the Raspberry Pi 4 firmware upgrade that reduced heat generation quite a bit. My two 4GB Raspberry Pi 4s have had no thermal issues. Running the same measurement script now, will report back the results. Edit: Ok, done with the tests. Both RPi4s are bare and should be running exactly the same versions. RPi4 #1 started at 51C, peak 79C…

Yeah that's consistent with what I saw when I looked at the upgrade. Two degrees gained or so.

I gather the main temp gain isn't the CPU though but rather on the USB charging circuitry.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#75

Post by Havoc » Wed, Jun 10, 2020, 7:03 PM UTC

reitanqild wrote: post #5

Anyone has links to similar articles with regards to either - SD card reliability - techniques for reliably using what we have ? Given that people are using these for all kinds of stuff there must be some advanced techniques being used (or some basic I have missed).

Either network boot or SSD boot. The SD cards do eventually die. I've lost two already

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#76

Post by yjftsjthsd-h » Wed, Jun 10, 2020, 7:07 PM UTC

Arnt wrote: post #23

dannyw wrote: post #18

Why do people use cases on a Pi? I’ve never ever used a case. My Pis are always out of the way and in a shelf somewhere, untouched until I make modifications to the setup, in which case the case is often coming off anyway.

So the cleaners will touch the case, not the electronics. Also, the bare board doesn't offer a convenient way to fix the Pi to a wall IIRC.

> Also, the bare board doesn't offer a convenient way to fix the Pi to a wall IIRC.

My Pi 3 has little circular holes that I assume are meant to mount into a case, but which I have successfully used to just hang the board on a hook on the wall.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#77

Post by LeoPanthera » Wed, Jun 10, 2020, 7:09 PM UTC

rc4hobby wrote: post #21

Thermal engineer here. There absolutely no need to use fan cooling, humongous heatsinks or harebrained temperature controller schemes to cool the raspberry pi 4. All that is needed is a small heatsink to slightly decrease the thermal resistance to ambient air, to stay below the thermal throttling threshold. Anything more complicated than that is a pointless exercise in pointlessness.

Did you read the article? He tested a heatsink. I'll quote the relevant part.

> Heatsinks will generally shave 5-10°C off the highest temperatures you encounter, which is significant, but you still need to have air moving across the heatsink for it to do anything. This means either a fully open Pi (great for testing or tinkering, not so great for a semi-permanent installation), a well-ventilated case (with slots or holes in the bottom and top to allow natural convection), or a fan. So not a bad choice, and they're so cheap you should probably stick them on any Pi you can... but heatsinks alone won't solve Pi cooling problems.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#78

Post by arbitrage » Wed, Jun 10, 2020, 7:23 PM UTC

hajile wrote: post #73

rc4hobby wrote: post #21

Thermal engineer here. There absolutely no need to use fan cooling, humongous heatsinks or harebrained temperature controller schemes to cool the raspberry pi 4. All that is needed is a small heatsink to slightly decrease the thermal resistance to ambient air, to stay below the thermal throttling threshold. Anything more complicated than that is a pointless exercise in pointlessness.

Somebody's never overclocked their pi before... With an overclock, even a FLIRC would throttle when running our full unit test suite. A 30% reduction in unit test runtime is nothing to sneeze at and I certainly didn't want to downclock to 600-800MHz due to throttling. An ICE Tower was a lifesaver.

by overclock, do you mean full-out running at peak all the time? or letting the CPU governor still work and just bumping up the limits?

one makes sense, the other is hubris.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#79

Post by NortySpock » Wed, Jun 10, 2020, 8:06 PM UTC

Arnt wrote: post #24

rc4hobby wrote: post #21

Thermal engineer here. There absolutely no need to use fan cooling, humongous heatsinks or harebrained temperature controller schemes to cool the raspberry pi 4. All that is needed is a small heatsink to slightly decrease the thermal resistance to ambient air, to stay below the thermal throttling threshold. Anything more complicated than that is a pointless exercise in pointlessness.

Would you describe that flirc case as complicated? To a naïve layman, it seems like the smallest all-metal case that'll fit the rpi4, made so that the metal acts as a heatsink. Which may be more heatsink area than a 15W CPU needs, but not bigger case area than is needed. Is there something I'm missing?

I believe the FLIRC case is custom designed for the RPi4, not just "happens to fit" as you imply. Otherwise you have it correct; it's an aluminum case that mates down onto the CPU for direct passive cooling.

Note that it's clearly an injection-molded aluminum top-half and the bottom-half is plastic, just used to keep the dust out.

I would describe it as simple and elegant; fit for purpose.

Otherwise I'm quite happy to have a full passive cooling config, as currently my RPi home server must live in the kitchen/dinning room area due to space constraints.

Re: Way to keep your cool running a Raspberry Pi 4 (2019)

#80

Post by the_af » Wed, Jun 10, 2020, 8:37 PM UTC

dannyw wrote: post #18

Why do people use cases on a Pi? I’ve never ever used a case. My Pis are always out of the way and in a shelf somewhere, untouched until I make modifications to the setup, in which case the case is often coming off anyway.

I'm gonna go ahead and be the shallow person here: I kinda like the look of the cases. It's a shame the official case has the worst heat problem, because it looks the coolest to me.