wheel of reincarnation
[coined in a paper by T. H. Myer and I.E. Sutherland "On the Design of Display Processors", Comm. ACM, Vol. 11, no. 6, June 1968)] Term used to refer to a well-known effect whereby function in a computing system family is migrated out to special-purpose peripheral hardware for speed, then the peripheral evolves toward more computing power as it does its job, then somebody notices that it is inefficient to support two asymmetrical processors in the architecture and folds the function back into the main CPU, at which point the cycle begins again.
Several iterations of this cycle have been observed in graphics-processor design, and at least one or two in communications and floating-point processors. Also known as `the Wheel of Life', `the Wheel of Samsara', and other variations of the basic Hindu/Buddhist theological idea. See also blitter, bit bang.