CPU Frequency Selector - Cinnamon CPU Frequency Selector Applet
Prime95 - Prime95 is a program that searches for new Mersenne prime numbers.
Udev Discover - A helping tool for udev testers, coders, hackers and consumers.
HeavyLoad - The individual test methods employed by HeavyLoad can be customized to fit your needs.
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.
Linpack Xtreme - Linpack Xtreme is a benchmark and the most aggressive stress testing software available today.