Figures 
and show the basic
idea of GRAPE systems. The special-purpose device performs only the
force calculation, while a general-purpose host computer takes care of
everything else. In the special-purpose device, a pipeline which
embodies the data flow for the force calculation calculates
interactions at the rate of one interactions per cycle (around 30
operations/cycle). Multiple pipelines can be attached to one memory
unit so that they calculate the force on different particles. With
multiple memory unit, it is also possible for multiple pipelines to
calculate partial forces on one particle.
Figure: The basic architecture of GRAPE
Figure: The force calculation pipeline
Table summarizes the history of GRAPE project. New machine has
become larger and more complex, but at the same time more
cost-effective, even when the improvement due to the advance in the
device technology is discounted.
Table: History of GRAPE project
For N-body simulations of planetary formation and globular clusters, GRAPE approach proved itself to be extremely effective. In fact, significant fraction of N-body studies in these fields are now performed on GRAPEs, and many new and important results are published. Many copies of GRAPE hardwares are now used for SPH and N-body simulations in cosmology, galactic dynamics and galaxy formation.