The distinction between supercomputers and mainframes is not a hard and fast one, but supercomputers generally focus on problems which are limited by calculation speed while mainframes focus on problems which are limited by input/output and reliability ("throughput computing") and on solving multiple business problems concurrently (mixed workload). The differences and similarities include:
* Both types of systems offer parallel processing. Supercomputers typically expose it to the programmer in complex manners, while mainframes typically use it to run multiple tasks. One result of this difference is that adding processors to a mainframe often speeds up the entire workload transparently.
* Supercomputers are optimized for complicated computations that take place largely in memory, while mainframes are optimized for comparatively simple computations involving huge amounts of external data. For example, weather forecasting is suited to supercomputers, and insurance business or payroll processing applications are more suited to mainframes.
* Supercomputers are often purpose-built for one or a very few specific institutional tasks (e.g. simulation and modeling). Mainframes typically handle a wider variety of tasks (e.g. data processing, warehousing). Consequently, most supercomputers can be one-off designs, whereas mainframes typically form part of a manufacturer's standard model lineup.
* Mainframes tend to have numerous ancillary service processors assisting their main central processors (for cryptographic support, I/O handling, monitoring, memory handling, etc.) so that the actual "processor count" is much higher than would otherwise be obvious. Supercomputer design tends not to include as many service processors since they don't appreciably add to raw number-crunching power.
There has been some blurring of the term "mainframe," with some PC and server vendors referring to their systems as "mainframes" or "mainframe-like." This is not widely accepted and the market generally recognizes that mainframes are genuinely and demonstrably different.
* Historically 85% of all mainframe programs were written in the COBOL programming language. The remainder included a mix of PL/I (about 5%), Assembly language (about 7%), and miscellaneous other languages. eWeek estimates that millions of lines of net new COBOL code are still added each year, and there are nearly 1 million COBOL programmers worldwide, with growing numbers in emerging markets. Even so, COBOL is decreasing as a percentage of the total mainframe lines of code in production because Java, C, and C++ are all growing faster.
* Mainframe COBOL has recently acquired numerous Web-oriented features, such as XML parsing, with PL/I following close behind in adopting modern language features.
* 90% of IBM's mainframes have CICS transaction processing software installed.[2] Other software staples include the IMS and DB2 databases, and WebSphere MQ and WebSphere Application Server middleware.
* As of 2004, IBM claimed over 200 new (21st century) mainframe customers — customers that had never previously owned a mainframe. Many are running Linux, some exclusively. There are new z/OS customers as well.
* In May, 2006, IBM claimed that over 1,700 mainframe customers are running Linux. Nomura Securities of Japan spoke at LinuxWorld in 2006 and is one of the largest publicly known, with over 200 IFLs in operation that replaced rooms full of distributed servers.
* Most mainframes run continuously at over 70% busy. A 90% figure is typical, and modern mainframes tolerate sustained periods of 100% CPU utilization, queuing work according to business priorities without disrupting ongoing execution.
* Mainframes have a historical reputation for being "expensive," but the modern reality is much different. As of late 2006, it is possible to buy and configure a complete IBM mainframe system (with software, storage, and support), under standard commercial use terms, for about $50,000 (U.S.). The price of z/OS starts at about $1,500 (U.S.) per year, including 24x7 telephone and Web support.
* Typically, a mainframe is repaired without being shut down. Also, memory, storage and processor modules of chips could be added or hot swapped without being shut down. It is not unusual for a mainframe to be continuously switched on for 6 months at a stretch.
The CPU speed of mainframes has historically been measured in millions of instructions per second (MIPS). MIPS have been used as an easy comparative rating of the speed and capacity of mainframes. The smallest System z9 IBM mainframes today run at about 26 MIPS and the largest about 17,801 MIPS. IBM's Parallel Sysplex technology can join up to 32 of these systems, making them behave like a single, logical computing facility of as much as about 569,632 MIPS.
The MIPS measurement has long been known to be misleading and has often been parodied as "Meaningless Indicator of Processor Speed." The complex CPU architectures of modern mainframes have reduced the relevance of MIPS ratings to the actual number of instructions executed. Likewise, the modern "balanced performance" system designs focus both on CPU power and on I/O capacity, and virtualization capabilities make comparative measurements even more difficult. See benchmark (computing) for a brief discussion of the difficulties in benchmarking such systems. IBM has long published a set of LSPR (Large System Performance Reference) ratio tables for mainframes that take into account different types of workloads and are a more representative measurement. However, these comparisons are not available for non-IBM systems. It takes a fair amount of work (and maybe guesswork) for users to determine what type of workload they have and then apply only the LSPR values most relevant to them.
To give some idea of real world experience, it is typical for a single mainframe CPU to execute the equivalent of 50, 100, or even more distributed processors' worth of business activity, depending on the workloads. Merely counting processors to compare server platforms is extremely perilous.
* Both types of systems offer parallel processing. Supercomputers typically expose it to the programmer in complex manners, while mainframes typically use it to run multiple tasks. One result of this difference is that adding processors to a mainframe often speeds up the entire workload transparently.
* Supercomputers are optimized for complicated computations that take place largely in memory, while mainframes are optimized for comparatively simple computations involving huge amounts of external data. For example, weather forecasting is suited to supercomputers, and insurance business or payroll processing applications are more suited to mainframes.
* Supercomputers are often purpose-built for one or a very few specific institutional tasks (e.g. simulation and modeling). Mainframes typically handle a wider variety of tasks (e.g. data processing, warehousing). Consequently, most supercomputers can be one-off designs, whereas mainframes typically form part of a manufacturer's standard model lineup.
* Mainframes tend to have numerous ancillary service processors assisting their main central processors (for cryptographic support, I/O handling, monitoring, memory handling, etc.) so that the actual "processor count" is much higher than would otherwise be obvious. Supercomputer design tends not to include as many service processors since they don't appreciably add to raw number-crunching power.
There has been some blurring of the term "mainframe," with some PC and server vendors referring to their systems as "mainframes" or "mainframe-like." This is not widely accepted and the market generally recognizes that mainframes are genuinely and demonstrably different.
* Historically 85% of all mainframe programs were written in the COBOL programming language. The remainder included a mix of PL/I (about 5%), Assembly language (about 7%), and miscellaneous other languages. eWeek estimates that millions of lines of net new COBOL code are still added each year, and there are nearly 1 million COBOL programmers worldwide, with growing numbers in emerging markets. Even so, COBOL is decreasing as a percentage of the total mainframe lines of code in production because Java, C, and C++ are all growing faster.
* Mainframe COBOL has recently acquired numerous Web-oriented features, such as XML parsing, with PL/I following close behind in adopting modern language features.
* 90% of IBM's mainframes have CICS transaction processing software installed.[2] Other software staples include the IMS and DB2 databases, and WebSphere MQ and WebSphere Application Server middleware.
* As of 2004, IBM claimed over 200 new (21st century) mainframe customers — customers that had never previously owned a mainframe. Many are running Linux, some exclusively. There are new z/OS customers as well.
* In May, 2006, IBM claimed that over 1,700 mainframe customers are running Linux. Nomura Securities of Japan spoke at LinuxWorld in 2006 and is one of the largest publicly known, with over 200 IFLs in operation that replaced rooms full of distributed servers.
* Most mainframes run continuously at over 70% busy. A 90% figure is typical, and modern mainframes tolerate sustained periods of 100% CPU utilization, queuing work according to business priorities without disrupting ongoing execution.
* Mainframes have a historical reputation for being "expensive," but the modern reality is much different. As of late 2006, it is possible to buy and configure a complete IBM mainframe system (with software, storage, and support), under standard commercial use terms, for about $50,000 (U.S.). The price of z/OS starts at about $1,500 (U.S.) per year, including 24x7 telephone and Web support.
* Typically, a mainframe is repaired without being shut down. Also, memory, storage and processor modules of chips could be added or hot swapped without being shut down. It is not unusual for a mainframe to be continuously switched on for 6 months at a stretch.
The CPU speed of mainframes has historically been measured in millions of instructions per second (MIPS). MIPS have been used as an easy comparative rating of the speed and capacity of mainframes. The smallest System z9 IBM mainframes today run at about 26 MIPS and the largest about 17,801 MIPS. IBM's Parallel Sysplex technology can join up to 32 of these systems, making them behave like a single, logical computing facility of as much as about 569,632 MIPS.
The MIPS measurement has long been known to be misleading and has often been parodied as "Meaningless Indicator of Processor Speed." The complex CPU architectures of modern mainframes have reduced the relevance of MIPS ratings to the actual number of instructions executed. Likewise, the modern "balanced performance" system designs focus both on CPU power and on I/O capacity, and virtualization capabilities make comparative measurements even more difficult. See benchmark (computing) for a brief discussion of the difficulties in benchmarking such systems. IBM has long published a set of LSPR (Large System Performance Reference) ratio tables for mainframes that take into account different types of workloads and are a more representative measurement. However, these comparisons are not available for non-IBM systems. It takes a fair amount of work (and maybe guesswork) for users to determine what type of workload they have and then apply only the LSPR values most relevant to them.
To give some idea of real world experience, it is typical for a single mainframe CPU to execute the equivalent of 50, 100, or even more distributed processors' worth of business activity, depending on the workloads. Merely counting processors to compare server platforms is extremely perilous.
3 comments:
stop copying and pasting your matter from wikipedia
Can you give me five reasion.
Why can’t Supercomputer replace Mainframe computers?
If yes then why? If no then why?
I really need answer
Good comparison between mainframe and super computers.
Mainframe Development
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