CMPEN 331 Quiz 1

Pipelining

Technique that allows the CPU to work on more than one instruction at a time

Amdahl's Law

Speedup 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

Volatile memory

Storage (such as RAM chips) that is wiped clean when power is cut off from a device.

Response time

How long it takes to do a task

Throughput

total work per unit time

Performance

1/execution time

Elapsed time

• Total response time, including all aspects

• Processing, I/O, OS overhead, idle time

• Determines system performance

CPU time

time spent processing a given job

CPU Time equation

CPU Clock Cycles * Clock Cycle Time

(CPU Clock Cycles) / (Clock Rate)

Clock cycles

Instruction count * cycles per instruction (CPI)

What can affect Instruction Count>?

Algorithm, Programming Language, Compiler, instruction set

4 Parts of a CPU

CPU, main memory, I/O, system interconnection

CPU PArts

Control unit, ALU, registers (storage), and CPU interconnection

Power CPU

Capacitive Load Voltage^2 frequency

Power wall

We can't reduce voltage further and we can't remove more heat so we move to microprocessors

Characteristics of a benchmark

1. written in high level language

2. representative of a particular programming paradigm (systems, numerical, commercial)

3. Can be measured easily

4. Wide distribution

SPEC 2006

Benchmark suite that is an industry standard for processor intensive applications

Programs that spend most of their time doing computation rather than I/O

Amdahl's Law equation

Timproved = Taffected/improvement factor + Tunaffected

MIPS

millions of instructions per second, does not account for differences in ISA's between cmoputers and difference in complexity of instructions

MIPS equation

Instruction count / (execution time * 10^6)

Mega

10^6

Giga

10^9

ASSEMBLER

Translates symbolic version of instructions into the binary version

SRAM

Memory that is fast but less dense and more expensive than DRAM, used in cache in CPUq

DRAM

Random access to any location

Magnetic disk and Flash memory

Flash memory worse than DRAM but better than magnetic disk, both nonvolatile