mhz - Computer Definition
(MegaHertZ) One million cycles per second. It is used to measure the transmission speed of electronic devices, including channels, buses and the computer's internal clock. A one-megahertz clock (1 MHz) means some number of bits (1, 4, 8, 16, 32 or 64) can be manipulated at least one million times per second. A two-gigahertz clock (2 GHz) means at least two billion times. The "at least" is because multiple operations often occur in one clock cycle. Both megahertz (MHz) and gigahertz (GHz) are used to measure CPU speed. For example, a 1.6 GHz computer processes data internally (calculates, compares, copies) twice as fast as an 800 MHz machine. Why Isn't It Faster? A CPU in the new computer billed as two times faster than the old computer does not mean twice as much finished work gets done in the same time frame. Internal cache design, bus speed, disk speed and network speed all contribute to the computer's actual processing speed and performance (the overall throughput). Users are often dismayed to find only incremental improvements after purchasing a so-called "faster" computer. In addition, newer versions of software are sometimes slower than previous versions, and a faster computer is often required just to maintain the same performance level as the old software. See MIPS, Hertz and space/time. MHz and GHz Are the Heartbeat When referencing CPU speed, the megahertz and gigahertz ratings are really the heartbeat of the computer, providing the raw, steady pulses that energize the circuits. If you know German, it is easy to remember. The word "Herz," pronounced "hayrtz," means heart. This was a coincidence, because in 1883, Heinrich Hertz identified electromagnetic waves.