1.Memory System Desiderata
The Memory system has three desiderata.
(1)Size:infinitely large,no constraints on program of data set size.
(2)Speed:infinitely fast,latency equal to the fastest memory technolgy available.
(3)Cost:per bit cost should approach the lowest-cost technology available.
Clearly,these specifications cannot all be achieved as they are mutually exclusive.
However, with the semiconductor and magnetic memory technology of today,these
specifications are closely approximated.
1.Memory System Desiderata
The Memory system has three desiderata.
内存系统设计内存系统有三个设计。
(1)Size:infinitely large,no constraints on program of data set size.
（1）大小：无限大，对数据集大小的程序没有限制。
(2)Speed:infinitely fast,latency equal to the fastest memory technolgy available.
（2）速度：无限快，延迟等于最快的可用内存技术。
(3)Cost:per bit cost should approach the lowest-cost technology available.
（3）成本：每比特成本应接近可用的最低成本技术。
Clearly,these specifications cannot all be achieved as they are mutually exclusive.
显然，这些规格不可能全部实现，因为它们是相互排斥的。
However, with the semiconductor and magnetic memory technology of today,these specifications are closely approximated.
然而，随着当今半导体和磁存储技术的发展，这些规范得到了密切的近似。
1.3 存储器
1.存储系统的需求
存储系统有一下3项需求。
（1） 容量：无限大，对程序和数据集大小没有任何约束。
（2） 速度：无限快，等待时间在现有存储器技术下是最短的。
（3） 价格：每位的价格在可使用的技术中应最低。
很明显，由于这3个需求相互制约，所以很难全部满足。不过随着半导体和磁存储技术的发展，这些需求几近得到满足。