Throughput
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In the business management theory of constraints, throughput is the rate at which a system produces money, in contrast to output, which may be sold or stored in a warehouse. The signal provided by throughput is received (or not) at the point of sale -- exactly the right time. Output that becomes part of the inventory in a warehouse may mislead investors or others about the organization's condition by inflating the apparent value of its assets. The theory of constraints and throughput accounting explicitly avoid that trap.
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In information technology, throughput is the rate at which a computer or network sends or receives data. It therefore is a good measure of absolute performance, and we frequently will see internet connections rated in terms of how many bits they pass per second (bit/s).
However it is a very bad measurement of perceived speed, which is mostly based on how quickly it responds to you. Responsiveness has far less to do with throughput than latency. As the classic example goes, a station wagon full of magnetic tape has excellent throughput and horrible latency. It may take a week to deliver data from California to New York, but can carry so much that the throughput is better than broadband. Yet a user who has to wait a week to see a web page will complain that they preferred their much faster dialup connection!
Normally throughput and latency are opposed goals. To improve latency you typically want to increase how much the computer checks to see if you are trying to interact. This checking overhead slows you down. However there is one very common exception to this rule. Network protocols and programs tend to synchronize both ends regularly. If these synchronizations are slow, then throughput can suffer horribly.
See also
External link
- It's the Latency, Stupid (http://www.stuartcheshire.org/rants/Latency.html)ja:スループット