What is vector processing and how does it accelerate computer code?

[Cerxes]

What is "vectorized computer code"?

 

[shoehorn]

Wikipedia has a very elementary description of it here.

 

[rcgldr]

Also refer to:

http://en.wikipedia.org/wiki/Vector_processor

The artilcles mention picking up multiple operands at the same time, but this depends on the width (how many bits) of the bus holding the operands. On vector processors the operands are pipelined into separate math processors, so the math processors can operate in parallel. If there are enough math processors, then math operations effectively occur as fast as the operands can be read from memory.

As noted in the vector processing article, instead of storing results, additional math operations can be peformed, such as summation of all the products produced in a vector multiply, a key component of matrix multiplaction. Each row / column combination are processed in parallel.

Note that scoreboarding can be used to coordinate the outputs from vector operations. The CDC 6000 series included scoreboarding, and date back to 1964, predating the IBM 360 by almost a year. (IBM announced their 360's in April of 1964, but never shippped any models until mid 1965, essentially the 1964 360's were "paper machines", they never existed).

http://en.wikipedia.org/wiki/Scoreboarding