kHz, MHz, GHz (Clock Frequency)

4004 worked at a clock frequency of 108kHz
The latest processors have clock freqs. in GHz
Out of 2 microprocessors  having similar designs, one with higher clock frequency will
be more powerful   
Same is not true for 2 microprocessors  of dissimilar designs.  Example:  Out of
PowerPC & Pentium 4 microprocessors working at the same freq, the former performs
better due to superior design.  Same for the Athlon microprocessor when compared with
a Pentium.