Assignment
(Supercomputer & Mainframe Computers)
Supercomputer:
The
fastest and most expensive computers available at any given time are called Supercomputers. This is not a
satisfactory definition but we are forced to use such a definition computer
technology has been evolving rapidly. In the past 20 years there has been a
thousand folds increase in the speed of arithmetic operations of computers, and
it is therefore difficult to give a time invariant definition of the speed of a
supercomputer. Although the cost of computers for a specified speed and size
has been going down, typically the cost of computers of supercomputers has remained constant, around US $ 10 million.
Currently (1998), for a computer to be called supercomputer it must have the following characteristics:
High
computing speed: The computing speed of a supercomputer is
measured in gigaflops. A Giga is a billion and Flops is an abbreviation for
floating point operations per second. A
floating point operation is an
arithmetic operations (add, subtract, multiply or divide) on depends which are
real numbers with fractional parts. The operands are expressed as a pair
(mantissa, exponent). For example, the number 185.67827 which equals 0.18567827
X 10^3 is expressed as (0.18567827, 3), where 0.18567827 is the mantissa and 3
is the exponent. In supercomputers, the number of digits in the mantissa is 16,
where it is 8 in other computers, such as personal computers, workstations and
mainframe computers normally used in computing laboratories.
High
precision of stored numbers: we mentioned that supercomputers use 16
digits for the mantissa which is double the number normally used in other
computers. One may wonder why such a high precision for representing numbers is
needed. The reason is the possibility of accumulation of the small rounding errors
made by the computer while performing arithmetic operations. The larger the
number of arithmetic operations, the larger will be the accumulation of errors.
Large,
fast secondary memory: A supercomputer, nowadays, consists of a
number of processors connected together, all of them working together to solve
a single problem.
Large,
fast secondary memory: As the computation speed of
supercomputers is high, the data to be processed must be readily available in
the main memory. For a processing speed of 2 gigaflops, a maximum of 2 billion
pairs of operands would be needed per second, and all of them cannot be stored
in the main memory. As data is retrieved from the main memory and processed,
new data should be moved to the main memory from the secondary memory. The size
of the secondary should be large and the speed with which data is to be transferred
to the main memory should be compatible with the speed of the main memory.
Mainframe
Computers:
Today, mainframe computers play a central role in the daily operations
of most of the world’s largest corporations. While other forms computing are
used extensively in business in various capacities, the mainframe occupies a
coveted place in today’s e-business environment. In banking, finance, health
care, insurance, utilities, government, and a multitude of other public and
private enterprises, the mainframe computer continues to be foundation of
modern business.
The mainframe owes much of its popularity and longevity
to its inherent reliability and stability, which is a result of careful and
steady technological advances that have been made since the introduction of the
system/360 in 1964. No other computer architecture can claim as much
continuous, evolutionary improvement, while maintaining compatibility with
previous releases. Because of these design strength, the mainframe is often
used by IT organizations to host the most important, mission-critical
applications. These applications typically include customers order processing,
financial transactions, production and inventory control, payroll and many
other types of work.
One common impression of a mainframe’s user interface is
the 80X24-charcter “green screen” terminal, named for the old cathode ray tube
monitors from years ago that glowed green. In reality, mainframe interface today
look much the same as those for personal computers or UNIX systems. When a
business application is accessed through a web browser, there is often a
mainframe computer performing crucial functions “behind the scene”. Many of
today’s busiest websites store their production databases on a mainframe host.
New mainframe hardware and software products are ideal for web transactions
because they are designed to allow huge numbers of users and applications to
rapidly and simultaneously access the same data without interfering with each
other. This security, scalability and reliability is critical efficient and
secure operation of contemporary information processing. Corporations use
mainframe for applications that depends on scalability and reliability. For example,
a banking institution could use a mainframe to host the data base of its
customer accounts, for which transactions can be submitted from any of thousand
of ATM locations worldwide. Businesses today rely on the mainframe to:
Ø Perform large scale transaction processing.
Ø Support thousands of users and application programs
concurrently accessing numerous resources.
Ø Manage terabytes of information in data bases
Ø Handle large-bandwidth communication.
Comments
Post a Comment