TMonitor graphs your CPU speed in real time, shows Intel Turbo Boost
The usual go-to tool for CPU analysis is CPUID's CPU-Z utility -- but if you just want to measure your clock speed, CPU-Z can be a bit overkill. It also doesn't tell you a whole lot, other than the max CPU speed set in your BIOS.
Enter TMonitor -- download it, run it! For a start, did you know that your CPU idles way below your 'max' clock speed? My CPU is set at 3.8GHz in BIOS, but right now it's sitting at just 2.2GHz. The moment I do anything that involves the CPU, it speeds up -- interesting, considering SpeedStep is turned off.
TMonitor, as you can see from the picture, also measures every physical core (but not Hyper-Threads, seemingly) -- and it works with both multi-core AMD and Intel chips. If you have a recent Intel chip however, TMonitor will also show 'Turbo Boost' in action (some programs only use one core, so the chip speeds up that one core and powers down the others).
It's a neat little app, and I'm sure the perfect thing for overclockers -- or simply enthusiasts that are interested in the inner workings of their computer!