Access time is the time delay or
latency between a request to an electronic system, and the access being initiated or the requested data returned.
In
computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...
and
software systems, it is the time interval between the point where an
instruction control unit initiates a call to retrieve
data
Data ( , ) are a collection of discrete or continuous values that convey information, describing the quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted for ...
or a request to store data, and the point at which delivery of the data is completed or the storage is started. Note that in
distributed software systems or other systems with
stochastic processes, access time or latency should be measured at the ''99th percentile''.
''
See also
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Memory latency
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Mechanical latency
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Rotational latency
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: #Access time, access time and #Data transfer rate, data transfer time (o ...
*
Seek time
References
Network access
Engineering concepts
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