Friday, February 26, 2010

SUPER COMPUTERS

SUPERCOMPUTERS :
A supercomputer is the fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require large amounts of mathematical calculations. The chief difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently.

Some Common Uses of Supercomputers :

Supercomputers are used for highly calculation-intensive tasks such as problems involving quantum mechanical physics, weather forecasting, climate research, molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals), physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion), cryptanalysis, and many others. Some supercomputers have also been designed for very specific functions like cracking codes and playing chess; Deep Blue is a famous chess-playing supercomputer. Major universities, military agencies and scientific research laboratories depend on and make use of supercomputers very heavily.

Hardware and Software Design:

Supercomputers using custom CPUs traditionally gained their speed over conventional computers through the use of innovative designs that allow them to perform many tasks in parallel, as well as complex detail engineering. They tend to be specialized for certain types of computation, usually numerical calculations, and perform poorly at more general computing tasks. Their memory hierarchy is very carefully designed to ensure the processor is kept fed with data and instructions at all times - in fact, much of the performance difference between slower computers and supercomputers is due to the memory hierarchy. Their I/O systems tend to be designed to support high bandwidth, with latency less of an issue, because supercomputers are not used for transaction processing.
Supercomputer designs devote great effort to eliminating software serialization, and using hardware to address the remaining bottlenecks.

Supercomputer challenges:
A supercomputer generates large amounts of heat and therefore must be cooled with complex cooling systems to ensure that no part of the computer fails. Many of these cooling systems take advantage of liquid gases, which can get extremely cold.
Another issue is the speed at which information can be transferred or written to a storage device, as the speed of data transfer will limit the supercomputer's performance. Information cannot move faster than the speed of light between two parts of a supercomputer.
Supercomputers consume and produce massive amounts of data in a very short period of time. Much work on external storage bandwidth is needed to ensure that this information can be transferred quickly and stored/retrieved correctly.


Operating Systems and Programming:
Most supercomputers run on a Linux or Unix operating system, as these operating systems are extremely flexible, stable, and efficient. Supercomputers typically have multiple processors and a variety of other technological tricks to ensure that they run smoothly.
Until the early-to-mid-1980s, supercomputers usually sacrificed instruction set compatibility and code portability for performance (processing and memory access speed).For the most part, supercomputers had vastly different operating systems. The Cray-1 alone had at least six different proprietary OSs largely unknown to the general computing community. Similarly different and incompatible vectorizing and parallelizing compilers for Fortran existed.
The base language of supercomputer code is generally Fortran or C, using special libraries to share data between nodes. Software tools for distributed processing include standard APIs and open source-based software solutions which facilitate the creation of a supercomputer from a collection of ordinary workstations or servers.


Processing Speeds:
Supercomputer computational power is rated in FLOPS (Floating Point Operations Per Second). The first commercially available supercomputers reached speeds of 10 to 100 million FLOPS. The next generation of supercomputers is predicted to break the petaflop level. This would represent computing power more than 1,000 times faster than a teraflop machine. A relatively old supercomputer such as the Cray C90 (built in the mid to late 1990s) has a processing speed of only 8 gigaflops. It can solve a problem, which takes a personal computer a few hours, in .002 seconds! From this, we can understand the vast development happening in the processing speed of a supercomputer.
The is dedicated to providing information about the current 500 sites with the fastest supercomputers. Both the list and the content at this site is updated regularly, providing those interested with a wealth of information about the developments in supercomputing technology.

Supercomputer Architecture:
Supercomputer design varies from model to model. Generally, there are vector computers and parallel computers. Vector computers use a very fast data “pipeline” to move data from components and memory in the computer to a central processor. Parallel computers use multiple processors, each with their own memory banks, to 'split up' data intensive tasks.
A vector computer solves a series of problems one by one in a consecutive order whereas a parallel computer solves all the problems parallely as it is equipped with multiple processors. Hence, the parallel computer would be able to solve the problems much quicker than a vector computer.
Other major differences between vector and parallel processors include how data is handled and how each machine allocates memory. A vector machine is usually a single super-fast processor with all the computer's memory allocated to its operation. A parallel machine has multiple processors, each with its own memory.
Vector machines are easier to program, while parallel machines, with data from multiple processors, could have trouble with communication of data between them.
Recently, parallel vector computers have been developed to take advantage of both designs.
Manufacturers of Supercomputers:
There are many manufacturers of good supercomputers and Cray is one among them. Cray provides an informative with product descriptions, photos, company information, and an index of current developments.
IBM produces supercomputers with most cutting-edge technology. For information about IBM supercomputers Their "Blue Gene" supercomputer, is expected to run 15 times faster at 200 teraflops than their current supercomputers. IBM's "Blue Sky" which is called a self-aware supercomputer will be used to work on colossal computing problems such as weather prediction. Additionally, this supercomputer can self-repair, requiring no human intervention.
Intel has developed a line of supercomputers known as Intel TFLOPS. Supercomputers that use thousands of Pentium Pro processors in a parallel configuration to meet the supercomputing demands of their customers. To know more about Intel supercomputers.
R & D on Supercomputers:
IBM is developing the Cyclops64 architecture, intended to create a "supercomputer on a chip".
IBM's 20 PFLOPS supercomputer named "Sequoia" is scheduled to go online in 2011.
Supercomputers are projected to reach 1 exaflops (one quintillion FLOPS) in 2019.
A zettaflops (one sextillion FLOPS) computer required to accomplish full weather modeling might be built around 2030.

Wednesday, February 17, 2010

Types of Computers based on Configuration

Types of Computers based on Configuration:
There are four different types of computers when we classify them based on their performance and capacity. The four types are

Super Computers
Mainframe Computers
Mini Computers
Micro Computers

Super Computers:
When we talk about types of computers, the first type that comes to our mind would be Super computers. They are the best in terms of processing capacity and also the most expensive ones. These computers can process billions of instructions per second. Normally, they will be used for applications which require intensive numerical computations such as stock analysis, weather forecasting etc. Other uses of supercomputers are scientific simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic design, and analysis of geological data (e.g. in petrochemical prospecting). Perhaps the best known super computer manufacturer is Cray Research. Some of the "traditional" companies which produce super computers are Cray, IBM and Hewlett-Packard.

Mainframe Computers:
Mainframe computers can also process data at very high speeds vi.e., hundreds of million instructions per second and they are also quite expensive. Normally, they are used in banking, airlines and railways etc for their applications.

Mini Computers:
Mini computers are lower to mainframe computers in terms of speed and storage capacity. They are also less expensive than mainframe computers. Some of the features of mainframes will not be available in mini computers. Hence, their performance also will be less than that of mainframes.

Micro Computers:
The invention of microprocessor (single chip CPU) gave birth to the much cheaper micro computers. They are further classified into

Desktop Computers
Laptop Computers
Handheld Computers(PDAs)

Desktop Computers:
Today the Desktop computers are the most popular computer systems. These desktop computers are also known as personal computers or simply PCs. They are usually easier to use and more affordable. They are normally intended for individual users for their word processing and other small application requirements.

Laptop Computers:
Laptop computers are portable computers. They are lightweight computers with a thin screen. They are also called as notebook computers because of their small size. They can operate on batteries and hence are very popular with travellers. The screen folds down onto the keyboard when not in use.

Handheld Computers:
Handheld computers or Personal Digital Assistants (PDAs) are pen-based and also battery-powered. They are small and can be carried anywhere. They use a pen like stylus and accept handwritten input directly on the screen. They are not as powerful as desktops or laptops but they are used for scheduling appointments, storing addresses and playing games. They have touch screens which we use with a finger or a stylus.

Tuesday, February 16, 2010

Types of computer

TYPES OF COMPUTERS
Computers can be classified based on their principles of operation or on their configuration. By configuration, we mean the size, speed of doing computation and storage capacity of a computer.

Types of Computers based on Principles of Operation:
There are three different types of computers according to the principles of operation. Those three types of computers are

Analog Computers
Digital Computers
Hybrid Computers


Analog Computers:
Analog Computer is a computing device that works on continuous range of values. The results given by the analog computers will only be approximate since they deal with quantities that vary continuously. It generally deals with physical variables such as voltage, pressure, temperature, speed, etc
Digital Computers:
On the other hand a digital computer operates on digital data such as numbers. It uses binary number system in which there are only two digits 0 and 1. Each one is called a bit.
The digital computer is designed using digital circuits in which there are two levels for an input or output signal.
These two levels are known as logic 0 and logic 1.
Digital Computers can give more accurate and faster results.
Digital computer is well suited for solving complex problems in engineering and technology. Hence digital computers have an increasing use in the field of design, research and data processing.

Based on the purpose, Digital computers can be further classified as,
General Purpose Computers
Special Purpose Computers


Special purpose computer is one that is built for a specific application. General purpose computers are used for any type of applications. They can store different programs and do the jobs as per the instructions specified on those programs. Most of the computers that we see today are general purpose computers.

Hybrid Computers
A hybrid computer combines the desirable features of analog and digital computers. It is mostly used for automatic operations of complicated physical processes and machines. Now-a-days analog-to-digital and digital-to-analog converters are used for transforming the data into suitable form for either type of computation.For example, in hospital’s ICU, analog devices might measure the patients temperature, blood pressure and other vital signs. These measurements which are in analog might then be converted into numbers and supplied to digital components in the system. These components are used to monitor the patient’s vital sign and send signals if any abnormal readings are detected. Hybrid computers are mainly used for specialized tasks.

Monday, February 15, 2010

Basic Computer

What is computer?

Computer is a faster working electronic, programmable, data processing device. Computer cannot do anything independently. It acts on the instructions from the user and processes it, gives the result in the desired form.

Application of computer
Some of the applications of the computer are given below.

Maintenance of accounts and producing reports.
Purchasing and stock control in super markets and factories.
Library book issue management and information retrieval.
Computer aided diagnosis of diseases.
Bank accounts and instant customer service.
Organization of examinations and tabulation of results.
Computer aided design of building, plants, and machinery.
Weather forecasting.
Computer controlled machines.
Computer aided learning.
Word processing and desk top publishing.
Crime detection – finger print processing and image processing.

Computer system characteristics:

Perform complex and repetitive calculations rapidly and accurately.
Storage large amounts of data and information for subsequent manipulations.
Hold a program of a model which can be explored in many different ways.
Make decisions.
Provide information to the user.
Automatically correct or modify – by providing signals – certain parameters of a system under control.
Draw and print graphs, and
Converse with users through terminals.