CPU-Z

CPU-Z is a free utility that Windows users can use to analyze the central processing unit, the motherboard chipset, and the RAM on their PC. It is available for download here.

As this screen grab shows, CPU-Z quickly shows the user on the first 'CPU' tab, the number of cores on her or his PC, the core speed, the type of processor the PC is using. Choosing 'Clocks' for the drop down Tools menu at bottom will show the individual core speeds in realtime. Multiple cores allow a processor to run multiple instructions simultaneously.

The SPD tab (Serial Presence Detect) shows you the memory modules (printed circuit boards) and the different speeds at which they can be run. The current memory speed will be shown in the Clocks option under Tools as well.