Hacker News Reader

Comment by monocasa | Hacker News Reader

I don't think that the heat sinks are mandatory.

While I don't know about the Pi4, I've found that heatsinks are absolutely required for my uses of the Pi3s. In every situation where I've used a 3 I've had problems with them thermal-throttling down to a basically useless clock speed or just straight-up overheating and blowing. And I'm not overclocking. I don't feel safe using them in embedded applications without _at least_ a heatsink on the main CPU. My workbench Pi also has a small 5V fan on it.

Are the 4s different somehow? Or has every 3 I've purchased (somewhere around a dozen) been defective? (I don't have this issue with the Zeros.)

You forgot to mention what you use them for. My pi3 is inside a Lego case with no fan. I watch videos with it, use it as a git repo host and share files from it and have never had a problem. I never turn it off. But perhaps if it was compiling or something I'd need to worry.

It depends on the video. The pair of Pi units I currently have active (something from the v2 line and a 3B+) are being video players via LibreELEC (the third was a small server for DHCP, NTP, ad filtering DNS, etc, though those jobs are now done elsewhere as it kept eating SD cards).

For almost everything I've thrown at the 3 all has been well. The thermal throttle kicks in after a while playing 1080p HEVC clips and occasionally on 720p ones, and makes them skip badly until it has chance to cool down, but that is not unexpected (I'm surprised 720p works as well as it usually does) as those are fairly processing intensive formats and being decoded in software. h264 and other encodings play back for hours on end (1080p or less, the limit of my current TVs) without it getting too warm for comfort. This is in a bog-standard case, with vents but no extra heatsinks or fans.

When I have time to faf around (this is a busy month) I'll probably grab a 4 for the HEVC-in-hardware (though support for that in LibreELEC is only in Alpha versions ATM), and hand down the 3 (or put it away for some future project).

The Raspberry Pi 4 no longer has incremental thermal throttling and was capable of running under "normal" desktop usage loads without active cooling.

Under benchmarking cooling was required to stay under the 80deg C throttle limit.

Article referenced: https://blog.hackster.io/meet-the-new-raspberry-pi-4-model-b...

My experience is that the Pi 4 gets very hot. You touch it anywhere (USB port, Ethernet port) and it hurts.

I got a 40mm 5V Noctua fan for it and 3D printed a case that takes it. The thing now runs very cold. Idle CPU temperatures were about 60 degrees before, now loaded temperatures are around 40. Airflow is a big deal. (I am not using any heat sinks.)

Any chance you'd be willing to put up the files for the case somewhere? I have a 40mm fan and a Pi on the way that I'd like to put together.

It's this one: https://www.thingiverse.com/thing:3723481

I printed it honeycomb infill and no top/bottom layers (and also rotated it so it printed with the top and bottom on the bed, instead of upright; having to change that might be an artifact of the slicer I used, though; Simplify3D)

Is it possible to order without a facebook account? I'd like one but I don't use facebook.

I actually bought the official case and drilled out a hole for a Pi-Fan (you can get them on Amazon or most places that have Pi's and accessories), 1 1/8". I mounted the fan on the top case and plugged it into the 5V and GND GPIO pins, and it keeps the Pi nice and cool.

I'm working on a blog post and YouTube video with the full details, but it's not that difficult an operation, and I liked the look/size of the official Pi case more than a printed case or one of the thousands of knockoffs.

I do agree with the parent that a fan (active cooling) is absolutely necessary on the Pi 4, more so than any before, as the CPU is not the only part on the board putting out a lot more heat than previous generations—that heat needs to move somewhere.

Which pi3? The ones with the metal heatspreader?

This is a good question, because I'm not sure offhand if any of the ones which failed were the 3B+ with the new heat spreader on the CPU. I suspect they weren't, as that model only came out a bit of a year ago.

I _have_ had overheat issues with the updated 3B+, though it usually involves 720P video and/or an active RTL-SDR dongle. That's somewhat to be expected given the power draw and processor demands of such.

Got to say Pimoroni's Fan Shim [1] works well. It is easy to set up, and they have a python library with a systemd service that can auto start and stop the fan depending on the CPU temperature. While you can get away without cooling, the CPU will be throttled to pieces.

[1] https://shop.pimoroni.com/products/fan-shim

Neato.

Depends. I am holding off on using mine 24/7 until I have a suitable case with good airflow, and definitely looking into active cooling. The 4 runs a lot hotter than the 3+.

If you have available vertical space, I've printed a "cooling case" that works great with my pi 3b+ without heatsinks. It's shaped like a flower vase(wide top, narrow bottom). The top is open(think of it like a large, open drinking cup), and the pi sits in the very bottom. Two funnel-shaped openings(large inlet, small outlet) allow outside airflow directly onto the CPU and wifi chips.

So far it works at full load without throttling for at least the time span of a full length movie(my use-case is a plex media server). The concept is that exhaust heat leaving through the larger opening up top is heated(and expanding) air. The depressurized vase pulls cooler ambient air in through the 2 funnels, which strike the CPU and wifi module for a poor-mans "active cooling", albeit at much lower speeds than a motor-driven fan could provide.

The downside is required vertical; the case is 8 inches tall. This is several times the vertical height of the board itself, so it's a bit of a non-starter for small embedded device use-cases. If you have space to spare though, it might be worth a shot depending on your use-case.

Is there anything on top of it? If not, how do you deal with dust coming in from above when the pi isn't used that much (eg during the night) and the airflow lower?

I see them all over. I see them being sold. If they're an option they really ought to be explained somewhere upfront.

I think you only need them if you want to overclock.

Just because someone's selling something, doesnt mean you need to buy it.

My 4 runs at around 60C idle and hits 80C easily without overclocking (just regular loads). That is a bit too much for a tiny device (and a tiny plastic case).

How often are you reaching the 80C throttle limit? Have you installed the latest firmware update? It should keep the temps from hitting the ceiling, depending on usage.

Update information: https://www.retrorgb.com/raspberry-pi-4-firmware-update.html

This did not help me. Using the pi4 as a desktop based machine, even just for streaming, will regularly hit 80c.

That update is not final and causes USB3 issues.

Me experience is exactly the same. Usage is mainly watching Plex or other streaming video.

I got rid of the case and just nailed it to the wall with some space on either side as a stopgap measure. This has reduced the frequency of the throttling as indicated by the temp gauge on screen, but not entirely avoided it. I have plans to add cooling this weekend.

This is with all upgrades as of today.

Them being in the base kits they sell implies otherwise. That's my frustration.

I mean, the raspberry pi foundation sells cases, but doesn't sell heatsinks AFAIK. It's hard to say they're in the base kit.

Reply on news.ycombinator.com