A reference point. Originally, a mark on a workbench used to compare the lengths of pieces so as to determine whether one was longer or shorter than desired. For computers, a benchmark is a test, or set of tests, designed to compare the performance of one computer system against the performance of others. A benchmark is not necessarily a capacity planning tool. That is, benchmarks may not be useful in attempting to guess the correct size of a system required for a particular use. In order to be effective in capacity planning, it is necessary for the test to be easily configurable to match the targeted use. In order to be effective as a benchmark, it is necessary for the test to be rigidly specified so that all systems tested perform comparable work. These two goals are often at direct odds with one another with the result that benchmarks are usually useful for comparing systems against each other, but some other test is often required to establish what kind of system is appropriate for an individual's needs