A few years ago, this book could have covered memory in a page or two. All memory came as discrete chips, and there were only a few sizes and speeds available. You bought however many chips you needed, installed them, and that was that.
Dramatic CPU speed increases over the last few years have brought designers up against one hard fact. It's difficult to design faster CPUs, but it's even harder to build faster memory. Building affordable fast memory is harder still. Faster processors require faster memory, so engineers have come up with various methods to increase memory speeds. One result is that memory isn't a simple issue any more. This chapter tells you what you need to know to make good decisions about buying memory when you build or upgrade a system.