Very interesting to see that this is a cross problem. I doubt that we can find a fix via software in a little amount of time. I’ve bought this heatsink :
Is there a good contact between CPU and heatsink? Have you used thermal compound?
Have you tried using different heatsink? E.g. Waveshare heatsink reduces CPU temperature by about 20°C for us (RPi Zero 2W) - https://www.waveshare.com/product/pi-zero-case-b.htm (it fits on Radxa Zero too but I’m not sure about 3W)
What’s your CPU usage? Isn’t there some very intensive process that overloads all CPU cores so even the heatsink does not manage to reduce the temperature enough?
Is there a good contact between CPU and heatsink ? yes
Have you used thermal compound ? No,I used the heatsink as is,as it has been sold.
Have you tried using different heatsink? E.g. Waveshare heatsink reduces CPU temperature by about 20°C for us (RPi Zero 2W) - https://www.waveshare.com/product/pi-zero-case-b.htm (it fits on Radxa Zero too but I’m not sure about 3W) : nope. I’ve ordered this one :
almost in idle mode.
Despite everything. If I buy something that claims to be able to perform the task for which I bought it and it doesn’t,there is a problem somewhere and this problem cannot be caused by me. And this is confirmed by the various complaints that I read on the net. For sure I can change something,but I didn’t read on the page of the vendor that I should add this or that new component. It should work as it has been sold. This is how usually works. Even more if the description says “especially built for the radxa zero 3W”. I can’t do anything else but glue the sticky plastic over the circuits and place the aluminum heatsink on top of it. There is no other way to do this.
Is interesting to monitor the temperatures if one installs the Linux version reccomended by the radxa developers : “radxa-zero3_debian_bullseye_xfce_b6.img” ; I will not do it,because I want to install and use FreeBSD.
The product seems to be right but please do not consider that it works just becasue seems.
The temp in the base of the heatsink has to be similar to CPU.
tell you becasue I had problems with thermal pad that do not transfer heat to heatsink.
I’ve installed FreeBSD on the Radxa 3W,not Linux. Probably FreeBSD does not have the driver which support the Socs internal sensors. So. I should low the temperature via hardware.