
"It is good for programmers to understand what goes on inside a processor. The CPU is at the heart of our career. What goes on inside the CPU? How long does it take for one instruction to run? What does it mean when a new CPU has a 12-stage pipeline, or 18-stage pipeline, or even a 'deep' 31-stage pipeline? Programs generally treat the CPU as a black box. Instructions go into the box in order, instructions come out of the box in order, and some processing magic happens inside. As a programmer, it is useful to learn what happens inside the box. This is especially true if you will be working on tasks like program optimization. If you don't know what is going on inside the CPU, how can you optimize for it? This article is about
what goes on inside the x86 processor's deep pipeline."
Member since:
2009-03-17
since we're nitpicking, by your own definition the 486 is superscalar; it had multiple functional units.
Superscalar refers to the ability of running multiple functional units (usually redundant ones) in parallel, which I believe the 486 couldn't. The rule of thumb usually is that a superscalar microarchitecture can support theoretical IPCs larger than 1.