Question

A nonpipelined system takes 300ns to process a task. The same task can be processed in a 5-segment pipeline with a clock cycle of 60ns. Determine the speedup ratio of the pipeline for 100 tasks

Answer 1

Answer:

Pipelined architecture is 1.667 times more speedy than non pipelined architecture.

Explanation:

There are five stages to to complete an instruction to execute in pipeline architecture. as

Stage 1:  Instruction Fetch

Stage 2: Instruction Decode

Stage 3: Execute

Stage 4: Memory Access

Stage 5 : Write Back

The pipeline architecture processed instruction as given below. Each Stage take 1 clock cycle, which is represented as CC.

                Stage 1           Stage 2         Stage 3         Stage 4            Stage 5

I1:              1cc                  2cc                 3cc                4cc                   5cc

I2              2cc                 3cc                  4cc               5cc                   6cc

I3              3cc                  4cc                 5cc              6cc                    7cc

I4              4cc                 5cc                  6cc              7cc                    8cc

each four Instructions set takes 8 Clock Cycles.

I5              9cc                  10cc                11cc               12cc                 13cc

I6              10cc                 11cc                  12cc             13cc                 14cc

I7              11cc                  12cc                 13cc              14cc                 15cc

I8              12cc                 13cc                  14cc              15cc                16cc

.

.

.

I97:             193cc            194cc              195cc              196cc               197cc

I98             194cc             195cc             196cc               197cc               198cc

I99            195cc             196cc              197cc              198cc               199cc

I100         196cc                197cc             198cc            199cc                 200cc

Pipelined architecture Time Calculation

So in pipeline architecture 100 instructions takes 200 clock cycles to execute.

1 Clock Cycle time period is = 60ns.

200 Clock Cycle =  60ns * 200 = 12000 ns

Non Pipelined architecture Time Calculation

1 task Time period= 300ns

100 task time period = 100 * 300 =  30000 ns

The difference between pipelined and non pipelined architecture time period is = 30000 - 12000 = 18000 ns

Speedup ratio

Speed up ratio= 30000/18000 =  1.667