Chapter THREE. Processors and Multiprocessing

Chapter Syllabus

3.1 How Processors Work

3.2 The Processor Performance Evolution

3.3 Logical Processors and Hyper-Threading Technology

3.4 Multiprocessor Servers

3.5 Mixing Processors

One of the core competencies required of an HP Accredited Integration Specialist (AIS) is this:

"Explain and recognize processor technologies."

This chapter will assist you in meeting this core competency by providing information on the following key objectives:

• Explain how processors work, including the function of these key components:

  • Execution unit

  • Control unit

  • Registers

  • Decode unit

  • Prefetch unit

  • Data cache

  • Branch target buffer

  • Bus unit

  • Instruction cache

• Explain how key processor innovations have improved processor performance, including the following concepts:

  • Pipelining

  • Superscaler processing

  • Hyper-pipelining

  • Dynamic execution

• Explain how logical processors work in conjunction with hyper-threading technology.

• Explain the technical concepts behind multiprocessor servers, including these key concepts:

  • Asymmetric multiprocessing (AMP)

  • Symmetric multiprocessing (SMP)

  • Tightly coupled

  • Loosely coupled

• Explain the key requirements to consider when mixing processor types in an industry-standard server.

To select the appropriate server for a particular task, you need to consider several factors related to the server processor, such as how processors work, what innovations make processors work faster, how processor types differ, and how multiprocessor servers differ from single-processor servers.

It may seem logical to assume that processor speed is the sole factor to consider when choosing a processor for a particular application. For example, it seems perfectly reasonable to assume that a server with a 1GHz processor will always perform better than a server with an 800MHz processor. However, this is not always the case. Many factors besides processor speed affect how well a processor performs in a particular situation.

This chapter explains those factors and examines concepts that you need to know to make sure you make the right processor decisions.