The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
+18 votes

The performance of a pipelined processor suffers if:

  1. the pipeline stages have different delays
  2. consecutive instructions are dependent on each other
  3. the pipeline stages share hardware resources
  4. All of the above
asked in CO & Architecture by Veteran (59.9k points)
edited by | 2.7k views

2 Answers

+26 votes
Best answer

Answer is D.

A: Yes. Total delay = Max (All delays) + Register Delay.

B: Yes, if data forwarding is not there.

C: Yes, like ID and EX shares ID/EX register.

answered by Boss (33.8k points)
edited by
can same register access cause structural hazard??
for c option it could be register (same) with renaming ..? structural hazard ?
i think yes

structural hazard due to resource conflict, a resource can be register or memory
Well, the register file has SEPARATE input and output ports (Hamacher 6th edition, chapter 5), so how register file can cause resource confilct ?

@Harsh Kumar What if you're writing and reading from the same register?

+11 votes
Option D)All Of The Above.

Pipeline suffer from options:-

A) Yes, As pipeline need to work in SYNC all stage should operate in same time. If there are stages taking different time, if there is a slower stage, all faster stage will be bottlenecked by the cycles the slowest stage takes.

B)Yes, As there could be DATA HAZARDS.
           eg: SUB R2,R4,R5
                 ADD R6,R2,R4 //here register r2 result will be dependent on first instruction.

C)Yes, IF(Instruction Fetch) and MEM(Main Memory) stage can cause STRUCTURAL HAZARDS and there may be a chance that both stages need Memory simultaneously, that's why many Arch. slipt the cache as INST cache and Data Cache.
answered by Active (4.4k points)
edited by

Related questions

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
49,443 questions
53,648 answers
70,910 users