We have four computers on the basis of size.
1.Super computers
2.Mainframe computers
3.Mini computers
4.Micro computers
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Let's know in detail.
1.Super computers:
Features:
A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation.
Most powerful, fastest, and also very expensive.
performance is measured in FLOPS(FLoating-point Operations Per Second)
Can perform more than 1 trillion calculations per second.
Parallel processing is done in this computer. It may use symmetric or Massive parallel processing
uses powerful operating system (LINUX) with lightweight kernel.
Supercomputers of the 21st century can use over 100,000 processors.
Supports more number of terminals at same time (more than 1000)
while working they may share memory or operating system or bus with processor.
A number of RISC (Reduced Instruction Set Computer) processor are used in supercomputer and its world length is 64 or more bit.
use of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.
advanced inputs, outputs,secondary storage with primary.
100’s of GB of RAM, 1000’s of GB of secondary storage
Examples: CRAY X-MP/24, NEC-500, PARAM, Fujitsu VP-2600/10,ANURAG.
2.Mainframe computers
Features:
Mainframes are designed to handle very high volume of data. it can be said one housed CPU.
Less powerful,smaller in size and less expensive than supercomputer.
resulting in high reliability and security
measured in millions of instructions per second (MIPS)
word length was 32-bit or more.
more number of input-output facilities with the ability to offload to separate engines.
supports virtualization (runs many instances in virtual environment without using physical devices)
supports hot swapping.
supporting hundreds, or even thousands, of users/processors simultaneously.
supports fault tolerant .
mostly used for transaction processing
Examples: z900, z990, System z9, and System z10, etc
3.Mini computers:
Features:
It is a general purpose machine with a smaller CPU than a mainframe and super
It can be used as midrange servers.
Its word lengths are usually 16 to 32 bits.
It has a transfer rate of about 4 million bytes/second.
It supports multi-tasking,multi-programming concept
It had 4-bits bus system called bit-slice architecture
It can support all high level languages.
It can support between 15 to 25/50 terminals.
The CPU speed is 100 kips to 500 MIPS (Million Instructions per second).
The main memory size ranges from 256kb to 32Mb.
Examples: MAI Basic4, DEC PDP and VAX Series, Prime Computer Prime 50, Data General Nova, Wang Laboratories 2200 and VS Series, etc.
4.Micro computers:
Features:-
mallest and cheapest computer compared to super or mainframe or mini.
it is general purpose machine and does not need dedicated room.
contains only one microprocessor so called microcomputer.
supports 16/32/64 bits system.
used with CUI/GUI operating system.
used inputs like keyboard,mouse with monitor.
used RAM as primary memory (256Kb or more) and magnetic disk/optical disk as secondary.
does not support more no. of terminals.
its microprocessor speed is from MHZ to GHZ.
used for small business,accounting, for home and word related problems
. used intel chip like 8008
supports multiprogramming, multitasking, real time processing etc.
it has many types like, PDA,LAPTOP,TABLET ETC
