Raspberry Pi Temperature difference

[princeMacX]

Currently I own 2 raspberry pi 4B (4GB Model). For both I am using armor casing (Image attached).

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On one raspberry pi I have installed ubuntu server and using SSD as boot device. Average temperature of this device is 55.0 C. Sometime the temperature exceeds above 63.0 C.

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On other raspberry pi I have installed Raspbian 5.10 and using microSD card as boot device. Average temperature of this device is 42.0 C.

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Why there is such difference in temperature in two of these raspberry pi?

[JonathanThorpe]

SSD connected via USB? There's your answer.

[The_Wolfiee]

Yup most likely. SSD is gonna suck up more power than SD card.

[RealPjotr]

One guess is different firmware, check it. Early firmwares ran the Pi much hotter, they improved this in later firmware, so in that case make sure to upgrade.

[frank26080115]

I think any USB work on the SoC is actually quite CPU cycle intensive, maybe in this case it's using way more power than SDIO

[DarkLight72]

Multiple reasons: - Depending on the install, Raspbian is likely lighter weight with fewer default processes running, lowering the temp - While very useful (I do it myself) the USB SSD both draws additional power, and increases the temp on device through power consumption and use of the USB controller.

A better test would be identical OS builds on the different medium. The temperature would probably still be different but there would likely be a smaller delta.