Open Hardware Monitor is an Open Source utility that will monitor temperature sensors, voltages, fan speeds, clock speeds, and CPU core load of your machine.

It fully supports most hardware monitoring chips found on many of today's mainboards, making it an all-around monitoring utility.

With Open Hardware Monitor, you will be able to monitor the CPU temperature by reading the core temperature sensors of Intel and AMD processors, ATI and Nvidia video cards, and SMART, hard drive temperature, which can also be displayed. The monitored values can be displayed in the main window, a customizable desktop gadget, or the system tray.

Similar:

How to Monitor GPU Temperatures Using Task Manager

How to Identify the Hardware in Your Computer

Three Ways to Find Out How Many Cores Your CPU has

Version History for Open Hardware Monitor:
http://openhardwaremonitor.org/