AMD's QuantiSpeed Architecture

QuantiSpeed™ Architecture

One of the most important aspects of a computer system is the amount of time it takes to complete any given task. The microprocessor is at the heart of the computer, supplying life to the system. For that reason, the microprocessor is a component in determining the effectiveness of a computer system to execute specific tasks in the shortest amount of time. This is referred to as real-world application performance. Application performance is a combination of two elements:

1. Clock frequency of the processor, measured in Megahertz, or Gigahertz

2. The amount of work the processor can accomplish in a given clock cycle, measured in instructions per clock cycle (IPC).

Contrary to a popular misconception, clock frequency alone does not determine application performance. Real-world application performance is the combination of both clock frequency and IPC. Without a doubt, different methods can be used to optimize the processor for application performance. AMD has worked to maintain a balanced approach to optimizing performance by increasing the amount of work done per clock cycle (IPC), while improving the operating frequency at the same time. The end result is a processor design that produces high IPC and high operating frequencies, the optimum combination to increase overall performance

At the heart of QuantiSpeed architecture is a nine-issue, superscalar, fully
pipelined core. This provides more pathways to feed application instructions into the
execution engines of the core, simply allowing the processor to complete more work in a
given clock cycle (high IPC). The delicate balance between the depth of the pathways
(pipelines) and operating frequency of the processor produces high levels of performance.
Longer pipelines alone translate into lower IPC, but high operating frequencies.
However, shorter pipelines alone result in increased IPC, but lower operating frequencies.
AMD Athlon XP and mobile AMD Athlon 4 processors are designed to maintain a
balanced approach between pipeline depth and processor frequency to provide
extraordinary levels of overall processor performance.

The whitepaper from AMD with more explanation on Quantispeed is available here