Generational Garbage Collection and the Radioactive Decay Model
“That is what happens when a conventional generational garbage collector is used for a program whose object lifetimes resemble the radioactive decay model. The collector simply assumes that young objects have a shorter life expectancy than old objects, and concentrates its effort on collecting the generations that contain the most recently allocated objects. In the radioactive decay model, these are the objects that have had the least amount of time in which to decay, so the generations in which they reside contain an unusually low percentage of garbage. For the radioactive decay model, therefore, a conventional generational collector will perform worse than a similar non-generational collector.”
Paper by William D. Clinger and Lars T. Hansen (PostScript)