Prime95 - Prime95 is a program that searches for new Mersenne prime numbers.
Linpack Xtreme - Linpack Xtreme is a benchmark and the most aggressive stress testing software available today.
System Stability Tester - System Stability Tester - Test your system's stability and performance by calculating millions of digits of Pi.
Novabench - NovaBench is a piece of analytical software that works to test the various limits of your computer. The software is completely free to use, and it runs at a lightning-fast pace. Read more about Novabench.
CPU Frequency Selector - Cinnamon CPU Frequency Selector Applet
CPU-Z - CPU-Z is a freeware that gathers information on some of the main devices of your system : Processor name and number, codename, process, package, cache levels.