SIMD

Single instruction, multiple data (SIMD), is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data points simultaneously. Thus, such machines exploit data level parallelism, but not concurrency: there are simultaneous (parallel) computations, but only a single process (instruction) at a given moment. SIMD is particularly applicable to common tasks like adjusting the contrast in a digital image or adjusting the volume of digital audio. Most modern CPU designs include SIMD instructions in order to improve the performance of multimedia use.

History

The first use of SIMD instructions was in vector supercomputers of the early 1970s such as the CDC Star-100 and the Texas Instruments ASC, which could operate on a "vector" of data with a single instruction. Vector processing was especially popularized by Cray in the 1970s and 1980s. Vector-processing architectures are now considered separate from SIMD machines, based on the fact that vector machines processed the vectors one word at a time through pipelined processors (though still based on a single instruction), whereas modern SIMD machines process all elements of the vector simultaneously.

Simd (dance)

The simd (Ossetian: симд), is an Ossetian folk group dance.Time signature 4/4, 2/4. The beauty of Simd is in the strict graphic outline of the dance, the contrast between black and white costumes, the softness of movements, the strictness of line formations, and the harmony created by all of the above. The Simds name names the State song and dance ensemble of South Ossetia “Simd” named after B. A. Galayev.

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SIMD (hash function)

SIMD is a cryptographic hash function based on the Merkle–Damgård construction submitted to the NIST hash function competition by Gaëtan Leurent. It is one of fourteen entries to be accepted into round two of the competition, but was not shortlisted for the third and final round.

The designer states that the "most important component of SIMD is its message expansion, which is designed to give a high minimal distance". The algorithm's speed is claimed to be 11-13 cycles per byte.

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