12-06-2013, 03:53 PM
Introduction to Computers - Hardware
Computers.ppt (Size: 253 KB / Downloads: 44)
What is a Computer?
Computer
Device capable of performing computations and making logical decisions
Computers process data under the control of sets of instructions called computer programs
Personal computers: economical enough for individual
Distributed computing: computing distributed over networks
Client/server computing: sharing of information across computer networks between file servers and clients (personal computers)
Computer Hardware
Various devices comprising a computer:
Keyboard, screen, mouse, disks, memory, CD-ROM, and processing units
Hardware Trends: every year or two the following approximately double (Moore’s Law):
Amount of memory in which to execute programs
Amount of secondary storage (such as disk storage)
Used to hold programs and data over the longer term
Processor speeds
The speeds at which computers execute their programs
Moore's Law
Defined by Dr. Gordon Moore during the sixties.
Predicts an exponential increase in component density over time, with a doubling time of 18 months.
Applicable to microprocessors, DRAMs , DSPs and other microelectronics.
Monotonic increase in density observed since the 1960s.
Moore's Law and Performance
The performance of computers is determined by architecture and clock speed.
Clock speed doubles over a 3 year period due to the scaling laws on chip.
Processors using identical or similar architectures gain performance directly as a function of Moore's Law.
Improvements in internal architecture can yield better gains than predicted by Moore's Law.
Memory
A large collection of circuits, each capable of storing bit
Cells (words): manageable units; typical size is 8 bits (1 byte), some machines are 16 bits (2 bytes) and some are 32 bits or 64 bits
Byte (8 bits), KB (kilobyte, 103 210 bytes), MB (Megabyte, 106 220 bytes), GB (Gigabyte, 109 230 bytes). Note: k ≠ K because 1000 ≠ 1024.