1. Computer architecture and computer organization

2. Computer architecture and computer organization
In describing computer systems, the distinction is often made between computer architecture and computer organization.
It is difficult to give precise definitions for each of these terms, but a consensus exists about the general areas covered by each.

3. Computer architetcure
Computer architecture refers to those attributes of a computer system, which are visible to a programmer, in other words, those attributes that have a direct impact on the logical execution of a program.
Computer organization refers to the operational units and their interconnections that realize the architectural specifications.

4. Attributes Architectural Organizational instruction set
number of bits used to represent various data types
I/O mechanisms
memory addressing techniques
Organizational
number and types of available execution units
employed instruction issue and completion policies
numbers and sizes of various internal registers, buffers and queues
type, size and organization of cache memory

5. Example Architectural issue: Organizational issue:
A decision, whether a computer has a multiply instruction or not
Organizational issue:
A decision, whether that instruction is implemented by a dedicated multiply functional unit or by the repeated use of an add functional unit

6. Importance of the decision
The organizational decision may be based on
the anticipated frequency of use of the multiply instruction
the relative speed of the two approaches
the cost and physical size of the dedicated multiply unit
There are many x86 architecture compatible processors, but their performance and price differs significantly