I’ve been following the privacy focused Linux Mobile scene for a while now.
I haven’t owned any Purism products but have used the Pinephone, Pinephone Pro and Furilabs FLX1, usually running Phosh.
My ultimate goal is still to get a liberty phone, although it’s a sizeable investment. However, apart from cost, my real concern is the issue of “running hot”.
Both Pinephone and Pinephone Pro frequently heated up to uncomfortable levels during normal use. The FLX 1 stays nice and cool similar to a more mainstream phone. I asked Furilabs if this was due to them using a Mediatek vendor kernel and someone in that group opined that the real differentiator is the cpu chip itself - that Pinephones use chips intended for single board computers and so will unavoidably run hot simply by virtue of that not being as much of a key consideration for SBCs.
I’m interested in Purism’s take on this:
Do you agree that running hot is more of a hardware than a software issue?
Anecdotally I have heard similar stories of Librem phones running hot. Anyone have personal experience they can post about on this topic?
Are there specific current or future measures intended to lower operating temperature, either software or hardware?
Any information helping to explore this topic much appreciated.
I have since replaced the thermal paste in the phone which has helped a bit. I recommend browsing the case forums and get a stl and have it 3D Printed in TPU. Which also helps to keep it cooler against the hands.
No, it is clearly both, hardware and software. You can restrict the CPUs to get lower temperatures. Restricting means less power consumption and so less temperatures. However, this is already done on L5, so that passive cooling is enough to not burn your hands. It’s still a not so comfortable temperature, but you also don’t want to loose more performance, because it is already a quiet low end hardware for such use case.
On the other hand, common software always has the ability to run your CPU hot or not. In example, the L5 stays warm when Idling (ist really okay), but once you open and idling your Firefox browser, it just takes few minutes and your phone is hot similar to playing games, even if the browser does nothing. So software clearly has an impact. So question 2) is also answered.
Not really. I mean if software like Firefox becomes more energy efficient, the phone also stays cooler. But there will always be software that runs the CPU hot and some software even need that calculation power to be smooth and so you don’t want to throttle already at 40°C. Maybe GLES3 can help a bit, which should be introduced “soon”.
I just can say, put your phone as much as possible into suspend and it will be as cold as your environment is and for the most short use cases (reading SMS/messenger, watching clock and back to suspend) it does not even get warm.
Having a fan nearby and holding the Librem 5 in front of it makes a huge difference in my experience! The metal frame carries a lot of heat out from the internals, so if you give it just a little bit of help dissipating that heat, the Librem 5 seems to cool down right away.
It’s just a matter of operating in the right ambient temperature and you are not in the optimal zone for your phone. Depending on the season, of course. And latitude. Maybe time of day too. Workaround is to move. Having a phone that keeps you warm is a beneficial feature, not a problem!
I’m afraid there’s no need to be creative - there already exists accessories for phone active cooling. Search for instance Asus ROG phone active cooling - or one of the cheaper alternatives. Rather large humps to add on the back of the phone
