Open Hardware Monitor is a free and open source hardware monitoring application that's straightforward.
Here are some screenshots to illustrate the features and user interface of this application:
Monitor PC hardware when it comes to temperatures, fan speeds, voltages. Screenshot of Open Hardware Monitor - 1474px · 1610pxSimple interface and options. Screenshot of Open Hardware Monitor - 1474px · 1610pxFree and Simple Software to Monitor the Conditions of a Computer. Screenshot of Open Hardware Monitor - 1474px · 1610pxFeatures and Purposes. Screenshot of Open Hardware Monitor - 1474px · 1610pxOpen Hardware Monitor: Other Benefits. Screenshot of Open Hardware Monitor - 1474px · 1610px