CMPEN 331 - Quiz 1

List and briefly define one of the techniques used in contemporary processors to increased speed

Pipelining: The execution of an instruction involves multiple stages of operation, including fetching the instruction, decoding the opcode, fetching operands, performing a calculation, and so on.

Briefly characterize Amdahl’s law.

Amdahl's law deals with the potential speedup of a program using multiple processors compared to a single processor. The law indicates the amount of speedup as a function of the fraction of code that can be executed in parallel.

Time improve = (Time affected / Improvement factor) + T unaffected

List the desirable characteristics of a bench mark program

a. It is written in a high-level language, making it portable across different machines.
b. It is representative of a particular kind of programming domain or paradigm, such as systems programming, numerical programming, or commercial programming.
c. It can be measured easily.
d. It has wide distribution.

What are the SPEC benchmarks?

This is a collection of benchmark suites is defined and maintained by the Standard Performance Evaluation Corporation (SPEC)

CPI - Cycles per instruction

(CPU Time X Clock Rate) / Instruction Count

CPU Time

Instruction Count X CPI X Clock Cycle Time

MIPS = Millions of Instructions per Second

Clock Rate / CPI * 10^6

Relative Performance (1/Exec Time)

“X is n times faster than Y”

Perf x / Perf y = Exec Time y / Execution Time x = n

Clock Cycles

Instruction Count X Cycles per Instruction

Weighted average CPI

Sigma i ( CPI i * (Instruction Count i / Instruction Count) )