This document contains 29 questions about parallel computing and processor organizations. The questions cover important topics like models of parallel computing including hypercube networks, mesh networks, and butterfly networks; shuffle exchange networks; cube connected cycle networks; terms related to parallelization like speedup and efficiency; task graphs and Gantt charts; differences between binary k-cubes and cube-connected networks; embeddings of graphs like trees and meshes into processor topologies like hypercubes and meshes; dynamic load balancing algorithms; deterministic and non-deterministic models; and the Coffman-Graham scheduling algorithm.

1. Question Bank: Parallel computing Faculty: Ayaz Ahmed Shariff K
Modules covered: Processor organizations, Mapping and Scheduling
1. What are three important models of parallel computing? Explain each one of them?
2. Explain the need of networks in parallel processing. Discuss about the following networks.
(a) Hyper tree networks (b) Hypercube Networks
(c) Mesh networks (d) Pyramid networks
(e) Butterfly networks (f) Shuffle exchange networks
3. Explain shuffle exchange network with 8 nodes?
4. Discuss about 24 cube connected cycle network?
5. Define the terms diameter, Bisection width, Number of edges per node, Max edge length,
speedup, parallelizability, efficiency?
6. Define the terms task graph, gantt chart, optimal schedule, simple task graphs, chain,
necklace, perfect shuffle, multistage network, Omega network, Dilation?
7. What is the difference between a binary k-cube and a cube-connected network of degree k?
8. Given a shuffle-exchange network, prove that if a shuffle link connects nodes i and j, then j is
a single-bit left cyclic rotation of i? Prove that the number of necklaces in an n-node shuffle
exchange network is O(2k / k)??
9. Show how to perform the perfect shuffle network’s exchange operation on a de-bruijn
network?
10. Is it possible for the average speedup exhibited by a parallel algorithm to be superlinear?
11. Embed a complete binary tree with 31 nodes in a 2D mesh, or prove no such embedding
exists?
12. With a block diagram, explain processor arrays?
13. Explain types of Multiprocessors with examples?
14. Write a block diagram of the sequent symmetry UMA multiprocessor?
15. How cache consistency is maintained in UMA Multiprocessors?
16. How processors communicate in multicomputers? Briefly discuss some popular
multicomputers?
17. Discuss the Flynn’s taxonomy for classifying for serial and parallel computer architectures
with simple block diagrams?
18. How to embed a complete binary tree of height 3 into a 2 D Mesh? Is it possible to embed a
tree greater than height 4 in a 2 D Mesh without increasing the dilation beyond 1?
19. Illustrate with example, embedding of binomial tree into 2 D mesh?
20. Discuss embedding of different graphs into hypercube processor organization with some
examples?
21. Prove that a dilation-1 embedding of complete binary tree of height n into hypercube of
dimension n+1 does not exist if n>1?
22. Prove that a binomial tree of height n can be embedded in a hypercube of dimension n such
that dilation is 1?
23. What are properties of encoding to embed rings and meshes into hypercube?
24. What is gray code? Does gray code provide solution to embed a mesh onto hypercube?
Explain the mapping of 4 X 8 mesh into a 32-node hypercube?

2. 25. Explain mapping of an 8 node ring into an 8-processor hypercube?
26. What are different dynamic load balancing algorithms on multicomputers?
27. What are deterministic models and non-deterministic models?
28. Illustrate Coffman-Graham scheduling algorithm with an example? Does Coffman graham
scheduling algorithm produce an optimal schedule?
29. What is task graph? Explain the importance of embedding one graph into another?