Fundamentals of Quantitative Design and Analysis - Computer Architecture: A Quantitative Approach - page 14

in 6.1 billion chips shipped in 2010, or roughly 20 times as many chips that shipped with 80x86
processors.
Genuine Computer Architecture: Designing The Organization
And Hardware To Meet Goals And Functional Requirements
The implementation of a computer has two components: organization and hardware. The term
organization includes the high-level aspects of a computer's design, such as the memory sys-
tem, the memory interconnect, and the design of the internal processor or CPU (central pro-
cessing unit—where arithmetic, logic, branching, and data transfer are implemented). The
term microarchitecture is also used instead of organization. For example, two processors with
the same instruction set architectures but different organizations are the AMD Opteron and
the Intel Core i7. Both processors implement the x86 instruction set, but they have very differ
ent pipeline and cache organizations.
The switch to multiple processors per microprocessor led to the term core to also be used
for processor. Instead of saying multiprocessor microprocessor, the term multicore has caught
on. Given that virtually all chips have multiple processors, the term central processing unit, or
CPU, is fading in popularity.
Hardware refers to the specifics of a computer, including the detailed logic design and the
packaging technology of the computer. Often a line of computers contains computers with
identical instruction set architectures and nearly identical organizations, but they differ in the
detailed hardware implementation. For example, the Intel Core i7 (see Chapter 3 ) and the In-
tel Xeon 7560 (see Chapter 5 ) are nearly identical but offer different clock rates and different
memory systems, making the Xeon 7560 more effective for server computers.
In this topic, the word architecture covers all three aspects of computer design—instruction
set architecture, organization or microarchitecture, and hardware.
Computer architects must design a computer to meet functional requirements as well as
price, power, performance, and availability goals. Figure 1.7 summarizes requirements to con-
sider in designing a new computer. Often, architects also must determine what the functional
requirements are, which can be a major task. The requirements may be specific features in-
spired by the market. Application software often drives the choice of certain functional re-
quirements by determining how the computer will be used. If a large body of software exists
for a certain instruction set architecture, the architect may decide that a new computer should
implement an existing instruction set. The presence of a large market for a particular class of
applications might encourage the designers to incorporate requirements that would make the
computer competitive in that market. Later chapters examine many of these requirements and
features in depth.