The processing time for a recirculating (serial processor
) is the length of the algorithm times the image size.
In the extreme case there will be as many streams of video as there are nodes in the iPSC/2, each processor will operate simply as a serial processor
, and the machine will be completely efficient with no wasted CPU time (other than that caused by the imperfections of the program and programmers).
If N is the number of processors, s is the amount of time spent (by a serial processor
) on serial parts of a program, and p is the amount of time spent (by a serial processor
) on parts of the program that can be done in parallel, then Amdahl's law says that speedup is given by Speedup = (s + p)/(s + p/N) = 1/(s + p/N), where we have set total time s + p = 1 for algebraic simplicity.
The flood of data projected on the battlefield of the 1990s will far exceed the computational capacity of existing serial processors
used with ESM and radar warning receivers and anti-radiation missiles.