That the power supply for the one running hotter is also warmer suggests more electricity is being consumed by that Pi.I have just set up 3 identical brand new Pi 5's (so identical that their MAC addresses only differ by the last hex digit).
I did some initial set up on them without any cooling (I didn't want to attach the cooler until I knew they were working fine), and at the time I noticed that 1 of them seemed to be running a bit hotter than the other 2, but it wasn't very scientific and I didn't worry.
Now all 3 have are in operation with standard Active Coolers attached, sitting next to one another in same orientation. They are headless with the non-desktop OS, updated to latest, with s-tui and stress added, and nothing else changed. They are working flat out (100% x 4 cores x 24 hours/day) running a program of my own creation (which is highly CPU bound). None of them are at concerning temperatures, but that same one from before runs consistently 8 to 10 degrees hotter than the other 2 -- typically 65-66 degC versus 57-58 degC. It is also spinning its fan around 6,000 rpm most of the time, while the other 2 tend to flip around between 2,500 to 4,000 rpm.
Also -- and I would never otherwise have noticed this -- the PSU (the standard 27W jobbie) powering the warmer PI is slightly warmer to touch. Again nothing concerning, but just odd.
Any possible reasons for this?
Is it possible that the thermal sensor of one Pi is calibrated differently and the difference in power consumption is solely due to fan speeds?
Alternatively, the silicon used in one Pi mighty be unlucky and simply consume more power.
One could obtain another data point by checking how much each CPU can be over clocked. On the other hand I don't like to over clock because I don't want to do anything that might reduce reliability.
Statistics: Posted by ejolson — Tue May 27, 2025 12:46 am