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Multiprocessor
systems
Objective



the multiprocessors’ organization
and implementation
the shared-memory in
multiprocessor
static and dynamic connection
networks
Structure of
Multiprocessor systems
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consists of N processors plus
interconnections for passing data
and control information among the
computers.
Up to N different instruction
streams can be active
concurrently.
The challenge is to put the N
processors to work on different
parts of a computation,
Structure of MIMD
The fastest
supercomputer

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located in the Alberta National
Laboratory in United States.
This computer is equivalent to
9000 Pentium processors
can handle 21,000x10^8
instructions per second.
Terminology

PE-to-PE
 Each
processor has its own
memory and uses a common bus
for intercommunication.
CRAY T3D
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Number of Processors
 128
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Performance per PE
 150

GB Memory (64 MB each PE)
Harddisk
 80

MFlops / PE
Main Memory
8

Processor Elements (PEs)
GB temporary disk space
Swap area
 35
GB permanent user disk space
PE-to-PE SIMD machine
configuration
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Same as an array computer.
The local memory is attached to its
own processor with an
interconnection network for
exchanging data.
The number of arithmetic
processors is equal to the number
of memory storages.
PE to PE SIMD
Processor-to-memory
with N processors and N
memories
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The Processor-to-memory parallel
machine with N processors and N
memories
Same as an array computer
without a control unit.
The local memory is separated
from its own processor and they
are linked up by an interconnection
network.
PE to Memory
Difference between
Multi-processors

MSIMD
 It
is called multiple-SIMD which
can be reconfigured into a number
of smaller independent SIMD
machines

Partitionable SIMD/MIMD
 be
partitioned into smaller
independent machines of different
sizes working in SIMD or MIMD
Simple Uni-processor
Memory access

Access to memory may be blocked
temporarily due to the conflicts in
the network or the accessed
memory module.
Three methods to solve
memory access
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Buffer network elements
 To
queue a request in the buffer
when a conflict occurs.

Deletion
 The
processors will delete all but
one of the conflicting requests

Either of the about schemes
reduces CPU performance.
Multiprocessor
interconnection
networks

A basic parallel processing system
consists of various processors to
be linked up by an interconnection
network to form interprocess
communication.
Example of static
network topologies
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The processors are predefined
with connection paths.
Classified as one-dimensional
such as Linear Array, twodimensional such as Ring, Star,
Tree, etc.
Static network (fixed)
Two-way switching box
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A dynamic network allows
processors to re-route the path
(That is why it is called dynamic).
The single-stage network is also
called a recirculating network.
Switching box
4x4 switching network
(Blocking)
Non-Blocking Network
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A non-blocking networking has its
ability to connect any input to
output
Example is a cross-bar.
Cross bar
Summary
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introduced multiprocessors with N processors
and M (or N) memory storages.
Interconnected by a network which can be
dynamic or static.
Dynamic network can be classified as a
blocking or non-blocking network.
Blocking network can be implemented through
switching boxes while non-blocking network
can be implemented by a cross-bar network.