CPUMon is a simple little gadget to monitor CPU performance from your desktop. It displays a real-time graph of CPU performance as well as current usage indicator. The display supports custom colors, alpha-blending, user defined update rates and more. Some of the features: transparency, alpha-blending, customizable colors, layout presets, form locking, constantly updated CPU speed for mobile processors, tray icon mode, statistics, memory usage, and much more.

Comes integrated together with "Carbonsoft cxCpu Processor Detection Toolkit", which provides:

CPU Explorer - detailed CPU information, supports multiple CPUs;

CPU Features - lists supported CPU features.