Editing Mainframe computer (section)

==Differences from supercomputers==
A [[supercomputer]] is a computer at the leading edge of data processing capability, with respect to calculation speed. Supercomputers are used for scientific and engineering problems ([[high-performance computing]]) which crunch numbers and data,<ref>[http://www.graphanalysis.org/ High-Performance Graph Analysis] Retrieved on February 15, 2012</ref> while mainframes focus on transaction processing. The differences are:
* Mainframes are built to be reliable for [[transaction processing]] (measured by [[Transaction Processing Performance Council|TPC]]-metrics; not used or helpful for most supercomputing applications) as it is commonly understood in the business world: the commercial exchange of goods, services, or money. A typical transaction, as defined by the [[Transaction Processing Performance Council]],<ref>[http://www.tpc.org/information/about/abouttpc.asp Transaction Processing Performance Council] Retrieved on December 25, 2009.</ref> updates a database system for inventory control (goods), airline reservations (services), or banking (money) by adding a record. A transaction may refer to a set of operations including disk read/writes, operating system calls, or some form of data transfer from one subsystem to another which is not measured by the processing speed of the [[CPU]]. Transaction processing is not exclusive to mainframes but is also used by microprocessor-based servers and online networks.
* Supercomputer performance is measured in [[floating point]] operations per second ([[FLOPS]])<ref>[http://www.top500.org/ The "Top 500" list of High Performance Computing (HPC) systems] Retrieved on July 19, 2016</ref> or in [[traversed edges per second]] or TEPS,<ref>[http://www.graph500.org/ The Graph 500]{{webarchive|url=https://web.archive.org/web/20111227021230/http://www.graph500.org/ |date=December 27, 2011}} Retrieved on February 19, 2012</ref> metrics that are not very meaningful for mainframe applications, while mainframes are sometimes measured in millions of instructions per second ([[instructions per second|MIPS]]), although the definition depends on the instruction mix measured.<ref>Resource consumption for billing and performance purposes is measured in units of a [[million service units]] (MSUs), but the definition of MSU varies from processor to processor so that MSUs are useless for comparing processor performance.</ref> Examples of integer operations measured by MIPS include adding numbers together, checking values or moving data around in memory (while moving information to and from storage, so-called [[input/output|I/O]] is most helpful for mainframes; and within memory, only helping indirectly). Floating point operations are mostly addition, subtraction, and multiplication (of [[IEEE 754-1985|''binary'' floating point]] in supercomputers; measured by FLOPS) with enough digits of precision to model continuous phenomena such as weather prediction and nuclear simulations (only recently standardized [[decimal floating point|''decimal'' floating point]], not used in supercomputers, are appropriate for [[monetary]] values such as those useful for mainframe applications). In terms of computational speed, supercomputers are more powerful.<ref>[http://www.top500.org/ World's Top Supercomputer] Retrieved on December 25, 2009</ref>

Mainframes and supercomputers cannot always be clearly distinguished; up until the early 1990s, many supercomputers were based on a mainframe architecture with supercomputing extensions. An example of such a system is the [[HITAC S-3800]], which was instruction-set compatible with [[IBM System/370]] mainframes, and could run the [[Hitachi VOS3]] operating system (a fork of [[MVS|IBM MVS]]).<ref>{{cite conference |last1=Ishii|first1=Kouichi|title=An Overview of the HITACHI S-3800 Series Supercomputer |url=https://link.springer.com/chapter/10.1007/978-3-642-77661-8_5 |date=1992|book-title=Supercomputer ’92|pages=65–81|editor-last=Meuer|editor-first=Hans-Werner|publisher=Springer |doi=10.1007/978-3-642-77661-8_5|isbn=978-3-540-55709-8 |last2=Abe|first2=Hitoshi|last3=Kawabe|first3=Shun|last4=Hirai|first4=Michihiro|url-access=subscription}}</ref> The S-3800 therefore can be seen as being both simultaneously a supercomputer and also an IBM-compatible mainframe.

In 2007,<ref>{{cite press release|url=http://www-03.ibm.com/press/us/en/pressrelease/21433.wss|archive-url=https://web.archive.org/web/20070429062025/http://www-03.ibm.com/press/us/en/pressrelease/21433.wss|url-status=dead|archive-date=April 29, 2007|title=Cell Broadband Engine Project Aims to Supercharge IBM Mainframe for Virtual Worlds|date=April 26, 2007}}</ref> an amalgamation of the different technologies and architectures for [[supercomputer]]s and mainframes has led to a so-called [[gameframe]].