U. Glaeser

John C. McCallum
National University of Singapore
4.1 Introduction
© 2002 by CRC Press LLC
4
Price-Performance of
Computer Technology
4.1 Introduction
Price • Performance • Applications
4.2 Computer and Integrated Circuit Technology
4.3 Processors
Measuring Processor Performance
4.4 Memory and Storage—The Memory Hierarchy
Primary Memory • Secondary Memory • Tertiary Memory
4.5 Computer Systems—Small to Large
4.6 Summary
When you buy a computer, you normally decide what to buy based on what the computer will do
(performance) and on the cost of the computer (price). Price-performance is the normal trade-off in
buying any computer.
Performance of a computer system is primarily determined by the speed of the processor. But, it may
also depend on other features, such as the size of the memory, the size of the disk drives, speed of the
graphics adapter, etc. You normally have a limited choice of speeds, sizes, and features that are available
within an approximate price budget.
A personal computer (PC) of today is much more powerful than supercomputers of several years ago.
The $5 million CRAY-1 supercomputer of 1976 [1,2] was rated at about 100–250 million floating-point
operations per second (MFLOPS) in performance. A $1,400 PC in 2001 [3] has a performance of about
200–1000 MFLOPS. The price-performance improvements have been due to better computer manufacturing
technologies and the large volume production of PCs, in the order of 100 million PCs compared
with only 85 CRAY-1 computers produced.
The incredible improvement in performance of computers over time has meant that the priceperformance
trade-off normally improves dramatically even in a short period. The improvement trends
have been predicted since 1965 by Moore’s Law, which originally applied to the number of transistors
on an integrated circuit doubling every 18 months [4]. The ability to predict the future price-performance
of a computer system is often more important than knowing the current price of a computer, unless you
need to buy your computer today. Therefore, the main thrust of this chapter is looking at historical price
and performance trends to help predict the future.
Technologies other than processor speed have also been involved in the improving price-performance
of computer systems. The capacity and cost of memory (currently using dynamic random access memory,
i.e., DRAM), and the capacity and cost of magnetic disk drives are also critical. This chapter will concentrate
on the price and performance of processors, memory, and storage.