Well the're likely to some of these:
- power supply unit
- cpu
- case (mobo)
However, not necessarily. My computer has three (I think) sensors, there is a CPU reading, a case reading, but also a meter which will continuously say 25° C, I don't know why. My computer has no reading for power supply.
In your screenshot, Temp3 is more than Temp2 by just a bit, and could just be an error. Generally, the hihest temp is CPU but a difference of just 1 degree could be an error anyway.
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