Note : Question one is compulsory. Answer any three from
the rest.
1(i) The execution times (in seconds) of four programs
on three computers are given below:
Execution Time (in seconds)
Program Computer A Computer B Computer C
P1 1 10 20
P2 1000 100 40
P3 500 1000 50
P4 100 500 100
Assume that 100,000,000 instructions were executed in
each of the four programs. Calculate the MIPS rating
of each program on each of the three machines. Based
on these ratings. Can you draw a clear conclusion regarding
the relative performance of the three computers?
(ii) Answer the following questions:
(a) What causes a processor pipeline to be underpipelined?
(b) What are the factors limiting the degree of superscalar
design?
(c) Compare the instruction set architecture in RISC
and CISC processors in terms of instruction formats
and addressing modes.
(d) Factors affecting cache hit ratio.
2 Compare the relative merits of the three cache memory
organizations:
(i) Fully-associative cache
(ii) Set-associative cache
(iii) Sector mapping cache
3. Answer the following questions on designing scalar
RISC or Superscalar RISC processors: [15]
(i) Why do most RISC integer units use 32 general-purpose
registers?
(ii) What are the design tradeoffs between a large
register file and a large D-cache?
(iii) Explain the relationship between the integer
unit and floating point unit in most RISC processors
with scalar or superscalar organization.
4. Answer the following questions on pipelining and
superscalar techniques:
(i) Speed-up factors and the optimal number of pipeline
stages for a linear pipeline unit.
(ii) Mechanisms for instruction pipelining. ]
5. Explain the following as applied to multiprocessors
and multicomputers:
· Buffering flow control using virtual cut through
routing
· Blocking flow control in warm hole routing
· Virtual networks and sub networks
6. Distinguish among the following vector processing
machines in terms of architecture and performance range:
(i) Full scale vector supercomputers
(ii) High-end mainframes or near supercomputers
(iii) Minisupercomputers or supercomputing workstations
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