The current processor frequency is set in a parameter “CPU Speed” (CPU Frequency (MHz), Processor Speed). As a rule, this is only an informational parameter that is a result of multiplication of other two parameters. For example, a value “200 MHz” indicates a result from the multiplication of the bus frequency “66 MHz” and multiplier 3. But sometimes this parameter allows monitoring the configuration of the rest parameters in this section. For example, it can be set to Auto or Manual. In the first case, all appropriate parameters have default values while in the second case you have an opportunity to set all necessary values yourself. Of course, to carry out overclocking, you have to use manual control of parameters.
AMD, having produces a line of processors Atlon XP, caused a confusion with the correct marking. For example, a processor, marked as Atlon XP 2100, actually have a frequency of 1,67 GHz (133 Mhz*12,5).
Thanks to various modern technologies, a processor with a nominal frequency of 1,67 GHz shows the results which correspond to the processors by Intel with a frequency of 2,1 GHz. But it is more likely a marketing strategy. In office applications, AMD processors show the results that are equal to the results of the appropriate processors by Intel. From the other side, AMD Company produces processors with unlocked multiplier. So, it is possible to overclock your old processor, for example AMD K5 (or Atlon XP 1700), on the basis of the appropriate capabilities of your motherboard.