Thermal considerations for Strato Pi Base server
The Raspberry Pi draws power and generates heat proportionally to CPU and GPU load.
The Strato Pi main regulator also generates heat proportionally to the total amount of
current that it has to supply to the Raspberry and, if present, external devices.
The thermal behaviour of Strato Pi Base server is dynamic and affected by operating
conditions and the external environment temperature.
The Raspberry Pi CPU has the ability to throttle down its clock speed once a certain core
temperature is reached. This prevents CPU overheating, also limiting the temperature
inside the enclosure, when the CPU load is high for a significant amount of time.
The following charts show the thermal behaviour of Strato Pi Base server in different
conditions, in a typical installation with the device under test installed in a standard, not
ventilated DIN cabinet:
• 35C and 45C ambient temperature (the ambient temperature is measured inside the DIN
cabinet, so it is the actual air temperature surrounding the Strato Pi Base server
enclosure)
• Raspberry Pi 3 Model B+ and Raspberry Pi 4 Model B
• very low CPU load compared to very high load (all four cores loaded at 100%).
In all cases the Raspberry Pi 4 Model B runs significantly warmer than the Raspberry Pi 3
Model B+. Unless the ambient temperature is low and ventilation is optimal, reducing the
CPU clock speed of the Pi 4 would be highly advisable.
Strato Pi Base server is also available with the SPBF10X Strato Pi Fan active cooling
option.
The effectiveness of the Strato Pi Fan depends on several factors, including the external
environment conditions, CPU/GPU load, and other electrical loads.
In general terms, the fan will significantly increase the airflow inside the enclosure, and
improve heat transfer away from the CPU and the other nearby components on the
Raspberry Pi board.
The CPU will run cooler than without Strato Pi Fan, and it will take longer and higher loads
to reach its throttling limits.
Under ideal conditions, Strato Pi Fan may reduce both the CPU temperature and the
average air temperature inside the enclosure by up to 15 °C.
Refer to the SPBF10X Strato Pi Fan User Guide for additional information.
All tests performed with Raspbian Buster Lite and, on Raspberry Pi 4, VL805 firmware version
000137ab.
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Strato Pi Base User Guide
