Hi guys! This week my Librem 5 (from the “Evergreen” batch I believe it was) that I had ordered in September 2019 was delivered to the door and I have been having fun with it.
I noticed that as reported in other locations online, this device has a tendency to run slightly warmer in my hand than some other mobile devices that I had in the past. It does not really bother me humanly, but I was curious where I could check the technical specifications for the minimum and maximum supported temperatures for the device, so that I could cross-reference the safe minimum/maximum against what I see in the “Usage” app (when running the default Phosh installation that it came with).
For example, when I built myself a PC a few years ago I was able to find online that in the technical specifications for the graphics card or for the motherboard, there would be a section noting what the expected temperature range for that component was. I’m guessing that if I looked at the individual components of the Librem 5 (CPU/GPU/radios/etc), maybe the manufacturers would give specific ranges, but I was wondering if there was any device-wide obvious place to look up the safe range for the device itself generally.
Moreso than only an answer, I am also partly hoping to learn where I should have looked for this information. Thanks!
Automatic shutdown doesn’t always work. Exactly one time, my GPU’s fan and throttling settings did not work correctly and it had to shut down. And besides that, knowing maximum temperature is still useful to know if the phone might be throttling itself or not, and to know how stressed the cooling is.
Even outside of the phone’s own heat, I personally (not OP) would be interested in knowing how well it might cope with high external temperatures. I have had phones throttle before due to it being too hot.
I never reached more than 52°C. For cooking it’s not hot enough since I still can hold that temperature in my hands. 52°C for CPU is much lower than it could be (80°C and even more are common on desktops) - but to not burn your hands it’s limited on this. I guess 54°C was just a heat spike for a moment.
Safe charging temperatures for battery is up to 45°C. The device doesn’t allow you to charge when hotter (the red blinking LED says “I don’t charge until temperature is lower”). The inner temperature of batteries itself can easily get up to 60°C without damaging it. At least if we can trust this information.
So everything should be fine. As long as temperatures don’t get any higher you don’t need to worry about (and if they do, the device don’t get damaged, but you may burn your hands). Only the charger temperature shouldn’t be higher.
Edit:
Charging on suspend is the best you can do for your battery as long as you don’t use it.
Thank you so much for your tranquilizing answers
Do you think it’s possible to “force” by settings to reduce temperature? Or if Purism will do that with updates to avoid uncomfortable handle?
Let’s say this way … technical possible absolutely, but I have no idea what’s needed to change it. That is a question for developers or someone who know much more about Linux or Coreboot than I do.
At the moment, mine idles at 32C. Mostly it stays in the 30’s. When it has to work it gets warmer, and it can get up to 40-something C. When I stream music in the car and/or when the weather is hot, it can go all the way into the upper 40’s. But I don’t recall it going well into the 50’s.
In my experience, when unused Librem 5 idles at 25-30°C depending on ambient temperature; can get a bit lower with suspend and higher with screen on. When under active use (like, web browsing for a while), it gets up to 50°C where CPU frequency gets reduced; under prolonged intense use (like compiling big stuff and using GPU a lot) it can get up to 60°C; it generally doesn’t go much higher than that since at that point intense throttling would pretty much make the device unusable.
The above was about the SoC temps. When it comes to battery temperature (marked as bq25890-charger-0), it shouldn’t ever get much higher than 40°C. If it does, you’re likely dealing with some abnormal situation, like CPU cores being pegged to 100% for some reason in the background; or intense use in high ambient temp not allowing the heat to dissipate. Battery charging stops automatically at around ~42°C IIRC.
just let me know: is it regular?
52°C for CPU is much lower than it could be (80°C and even more are common on desktops) - but to not burn your hands it’s limited on this. I guess 54°C was just a heat spike for a moment.