Computer performance: Difference between revisions

Revision as of 17:12, 6 January 2024

Revision as of 22:29, 15 April 2024

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{{Main|Availability}}

Availability of a system is typically measured as a factor of its reliability - as reliability increases, so does availability (that is, less [[downtime]]). Availability of a system may also be increased by the strategy of focusing on increasing testability and maintainability and not on reliability. Improving maintainability is generally easier than reliability. Maintainability estimates (Repairrepair rates) are also generally more accurate. However, because the uncertainties in the reliability estimates are in most cases very large, it is likely to dominate the availability (prediction uncertainty) problem, even while maintainability levels are very high.

=== Response time ===

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{{Main|Performance per watt}}

System designers building [[parallel computing|parallel computers]], such as [[Google search technology#Production hardware|Google's hardware]], pick CPUs based on their speed per watt of power, because the cost of powering the CPU outweighs the cost of the CPU itself.<ref>{{cite web |title=EEMBC -- the Embedded Microprocessor Benchmark Consortium |url=http://www.eembc.org/benchmark/consumer.asp?HTYPE=SIM |title=EEMBC -- the Embedded Microprocessor Benchmark Consortium |access-date=2009-01-21 |url-status=dead |archive-url=https://web.archive.org/web/20050327005323/http://www.eembc.org/benchmark/consumer.asp?HTYPE=SIM |archive-date=2005-03-27 |access-date=2009-01-21}}[http://news.cnet.com/Power+could+cost+more+than+servers,+Google+warns/2100-1010_3-5988090.html]</ref>

For spaceflight computers, the processing speed per watt ratio is a more useful performance criterion than raw processing speed.<ref>D. J. Shirley; and M. K. McLelland. [https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2656&context=smallsat "The Next-Generation SC-7 RISC Spaceflight Computer"]. p. 2.</ref>

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"The Incredible Shrinking CPU".

2004.

[http://www.realworldtech.com/page.cfm?ArticleID=RWT062004172947&p=5] {{Webarchive|url=https://web.archive.org/web/20120531101531/http://www.realworldtech.com/page.cfm?ArticleID=RWT062004172947&p=5 |date=2012-05-31 }}</ref>

where