Эпидемиология "синдрома Аспергера"

NYT -- A 1992 United States Department of Education directive contributed to the over-diagnosis of Asperger syndrome. It called for enhanced services for children diagnosed as being on the autism spectrum and for children with “pervasive developmental disorder — not otherwise specified (P.D.D.-N.O.S.),” a diagnosis in which children with social disabilities could be lumped. The diagnosis of Asperger syndrome went through the roof. Curiously, in California, where children with P.D.D.-N.O.S. were not given enhanced services, autism-spectrum diagnoses did not increase.

Математическое

А почему, спрашивается, всю компьютерную память не делают из того же материала, что процессорный кэш? Во сколько конкретно раз было бы дороже? Или там какие-то архитектурные ограничения?