Editing Supercomputer (section)

==Distributed supercomputing==
===Opportunistic approaches===
{{Main|Grid computing}}

[[File:ArchitectureCloudLinksSameSite.png|thumb|Example architecture of a [[grid computing]] system connecting many personal computers over the internet]]
Opportunistic supercomputing is a form of networked [[grid computing]] whereby a "super virtual computer" of many [[Loose coupling|loosely coupled]] volunteer computing machines performs very large computing tasks. Grid computing has been applied to a number of large-scale [[embarrassingly parallel]] problems that require supercomputing performance scales. However, basic grid and [[cloud computing]] approaches that rely on [[volunteer computing]] cannot handle traditional supercomputing tasks such as fluid dynamic simulations.<ref>{{Cite web|url=https://www.academia.edu/3991932|title = Chapter 03 Software and System Management|last1 = Rahat|first1 = Nazmul}}</ref>

The fastest grid computing system is the [[List of volunteer computing projects|volunteer computing project]] [[Folding@home]] (F@h). {{as of|2020|4}}, F@h reported 2.5&nbsp;exaFLOPS of [[x86]] processing power. Of this, over 100&nbsp;PFLOPS are contributed by clients running on various GPUs, and the rest from various CPU systems.<ref>{{cite web|url=https://stats.foldingathome.org/os|title=Client Statistics by OS|publisher=Stanford University|author=Pande lab|work=Folding@home|access-date=10 April 2020}}</ref>

The [[Berkeley Open Infrastructure for Network Computing]] (BOINC) platform hosts a number of volunteer computing projects. {{As of|2017|02}}, BOINC recorded a processing power of over 166&nbsp;petaFLOPS through over 762&nbsp;thousand active Computers (Hosts) on the network.<ref>{{Cite web |url=http://www.boincstats.com/stats/project_graph.php?pr=bo |website=BOINCstats |title=BOINC Combined |publisher=[[BOINC]] |access-date=30 October 2016 |postscript=Note this link will give current statistics, not those on the date last accessed. |url-status=dead |archive-url=https://web.archive.org/web/20100919090657/http://boincstats.com/stats/project_graph.php?pr=bo |archive-date=19 September 2010  }}</ref>

{{As of|2016|10}}, [[Great Internet Mersenne Prime Search]]'s (GIMPS) distributed [[Mersenne Prime]] search achieved about 0.313&nbsp;PFLOPS through over 1.3&nbsp;million computers.<ref>{{cite web |url=http://www.mersenne.org/primenet |title=Internet PrimeNet Server Distributed Computing Technology for the Great Internet Mersenne Prime Search |work=GIMPS |access-date=6 June 2011 }}</ref> The PrimeNet server has supported GIMPS's grid computing approach, one of the earliest volunteer computing projects, since 1997.

===Quasi-opportunistic approaches===
{{Main|Quasi-opportunistic supercomputing}}

Quasi-opportunistic supercomputing is a form of [[distributed computing]] whereby the "super virtual computer" of many networked geographically disperse computers performs computing tasks that demand huge processing power.<ref name=Kravtsov>{{cite web|last1=Kravtsov|first1=Valentin |last2=Carmeli |first2=David |last3=Dubitzky |first3=Werner |last4=Orda |first4=Ariel |last5=Schuster |first5=Assaf |author-link5=Assaf Schuster |last6=Yoshpa |first6=Benny|title=Quasi-opportunistic supercomputing in grids, hot topic paper (2007)|url=http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.135.8993|work=IEEE International Symposium on High Performance Distributed Computing|publisher=IEEE|citeseerx=10.1.1.135.8993 |access-date=4 August 2011}}</ref> Quasi-opportunistic supercomputing aims to provide a higher quality of service than [[Grid computing|opportunistic grid computing]] by achieving more control over the assignment of tasks to distributed resources and the use of intelligence about the availability and reliability of individual systems within the supercomputing network. However, quasi-opportunistic distributed execution of demanding parallel computing software in grids should be achieved through the implementation of grid-wise allocation agreements, co-allocation subsystems, communication topology-aware allocation mechanisms, fault tolerant message passing libraries and data pre-conditioning.<ref name=Kravtsov />