IoT PC: Open Hardware Monitor

Open Hardware Monitor - Core temp, fan speed and voltages in a free software gadget:

"The Open Hardware Monitor is a free open source software that monitors temperature sensors, fan speeds, voltages, load and clock speeds of a computer.

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The free Open Hardware Monitor software runs on Microsoft Windows with the .NET Framework version 2.0 and above. On Linux systems the Open Hardware Monitor requires Mono with WinForms."