4. Explain the role of each of the following in determining the speed of a computer:
RAM
Clock speed
Data on hard disk
Data on CD ROM
Data on floppy disk
RAM - As a computer processes data and instructions, it temporarily stores information internally, usually on silicon random-access memory, or RAM, chips--often called semiconductor memory. Usually mounted on the main circuit board inside the computer or on peripheral cards that plug into the board, each RAM chip may consist of as many as 16 million switches, called flip-flop switches that respond to changes in electric current. Each switch can hold one bit of data: high voltage applied to a switch causes it to hold a 1; low voltage causes it to hold a 0. This kind of internal memory is also called read/write memory. http://en.wikipedia.org/wiki/Random_access_memory
Every computer processor includes an oscillator that operates at a certain number of pulses per second. These pulses set the tempo for the processor; in most cases, a processor executes one or more instructions per clock cycle. Clock speeds are usually measured in millions of cycles per second (megahertz) or billions of cycles per second (gigahertz).
Average processor clock speeds have gone up quite a bit over the past 10 years. As recently as 1990, a high-performance IBM 8088 processor ran at less than 5MHz. Today, processors from Intel and other vendors routinely run well over 3GHz. http://en.wikipedia.org/wiki/Clock_speed
Computer data is frequently stored on a hard disk. Speed - 9 ms 100 MB/s 7200 RPM Capacity - 20-160 GB (for a 2001 computer). http://en.wikipedia.org/wiki/Hard_disk The CD Rom has a speed of - 80-250 ms 8 MB/s (52 xs) variable Capacity - 700 MB http://en.wikipedia.org/wiki/CD-ROM The Floppy Disk - Speed - 84 ms 62 KB/s 300 RPM Capacity - 1.44 MB
http://www.webopedia.com/TERM/f/floppy_disk.html