History of computing hardware: Difference between revisions

Revision as of 17:16, 17 December 2024

Revision as of 20:30, 4 January 2025

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A NeXT Computer and its [[object-oriented]] development tools and libraries were used by [[Tim Berners-Lee]] and [[Robert Cailliau]] at [[CERN]] to develop the world's first [[web server]] software, [[CERN httpd]], and also used to write the first [[web browser]], [[WorldWideWeb]].

Systems as complicated as computers require very high [[reliability engineering|reliability]]. ENIAC remained on, in continuous operation from 1947 to 1955, for eight years before being shut down. Although a vacuum tube might fail, it would be replaced without bringing down the system. By the simple strategy of never shutting down ENIAC, the failures were dramatically reduced. The vacuum-tube [[Semi-Automatic Ground Environment|SAGE]] air-defense computers became remarkably reliable – installed in pairs, one off-line, tubes likely to fail did so when the computer was intentionally run at reduced power to find them. [[Hot plugging|Hot-pluggable]] hard disks, like the hot-pluggable vacuum tubes of yesteryear, continue the tradition of repair during continuous operation. Semiconductor memories routinely have no errors when they operate, although operating systems like Unix have employed memory tests on start-up to detect failing hardware. Today, the requirement of reliable performance is made even more stringent when [[server farm]]s are the delivery platform.<ref>{{cite web |last=Shankland |first=Stephen |title=Google uncloaks once-secret server |website=CnetCNET |date=1 April 2009 |url=https://news.cnet.com/8301-1001_3-10209580-92.html |access-date=2009-04-01 |url-status=dead |archive-url=https://web.archive.org/web/20140716084210/http://www.cnet.com/news/google-uncloaks-once-secret-server-10209580/ |archive-date=2014-07-16}} "Since 2005, its [Google's] data centers have been composed of standard shipping containers—each with 1,160 servers and a power consumption that can reach 250 kilowatts." —Ben Jai of Google.</ref> Google has managed this by using fault-tolerant software to recover from hardware failures, and is even working on the concept of replacing entire server farms on-the-fly, during a service event.<ref>{{cite web |last=Shankland |first=Stephen |title=Google spotlights data center inner workings |website=CnetCNET |date=30 May 2008 |url=https://news.cnet.com/8301-10784_3-9955184-7.html?tag=nefd.lede |access-date=2008-05-31 |url-status=dead |archive-url=https://web.archive.org/web/20140818092344/http://www.cnet.com/news/google-spotlights-data-center-inner-workings/ |archive-date=2014-08-18}} "If you're running 10,000 machines, something is going to die every day." —Jeff Dean of Google.</ref><ref>{{cite web|title=Google Groups |url=https://groups.google.com/group/google-appengine/browse_thread/thread/a7640a2743922dcf?pli=1 |access-date=11 August 2015 |archive-url=https://web.archive.org/web/20110913014648/https://groups.google.com/group/google-appengine/browse_thread/thread/a7640a2743922dcf?pli=1 |archive-date=2011-09-13|url-status=live}}</ref>

In the 21st century, [[multi-core]] CPUs became commercially available.<ref>{{cite web |last=Shrout |first=Ryan |date=2 December 2009 |website=PC Perspective |url=https://pcper.com/2009/12/intel-shows-48-core-x86-processor-as-single-chip-cloud-computer/ |title=Intel Shows 48-core x86 Processor as Single-chip Cloud Computer|archive-url=https://web.archive.org/web/20100814203128/http://www.pcper.com/article.php?aid=825 |archive-date=2010-08-14 |url-status=live |access-date=2020-12-02}}<br/>{{*}}{{cite web |date=3 December 2009 |title=Intel unveils 48-core cloud computing silicon chip |work=BBC News |url=https://news.bbc.co.uk/2/hi/technology/8392392.stm |access-date=2009-12-03 |archive-date=2012-12-06 |archive-url=https://web.archive.org/web/20121206054225/http://news.bbc.co.uk/2/hi/technology/8392392.stm |url-status=live}}</ref> [[Content-addressable memory]] (CAM){{sfn|Kohonen|1980|p={{pn|date=August 2023}}}} has become inexpensive enough to be used in networking, and is frequently used for on-chip [[cache memory]] in modern microprocessors, although no computer system has yet implemented hardware CAMs for use in programming languages. Currently, CAMs (or associative arrays) in software are programming-language-specific. Semiconductor memory cell arrays are very regular structures, and manufacturers prove their processes on them; this allows price reductions on memory products. During the 1980s, [[CMOS]] [[logic gates]] developed into devices that could be made as fast as other circuit types; computer power consumption could therefore be decreased dramatically. Unlike the continuous current draw of a gate based on other logic types, a CMOS gate only draws significant current, except for leakage, during the 'transition' between logic states.{{sfn|Mead|Conway|1980|pp=11-36}}