CPU Frequency Selector - Cinnamon CPU Frequency Selector Applet
Geekbench - Geekbench 4 measures your hardware's power and tells you whether your computer is ready to roar. How strong is your mobile or desktop system?
Udev Discover - A helping tool for udev testers, coders, hackers and consumers.
UserBenchMark - Test, fix and upgrade your PC's performance.
Prime95 - Prime95 is a program that searches for new Mersenne prime numbers.
3DMark - 3DMark includes everything you need to benchmark your hardware in one app.