CM-5 Massively Parallel CM-5 Massively Parallel SupercomputerSupercomputer

ALAN MOSERALAN MOSER

Thinking Machines

Corporation

1993

CM-5 General InformationCM-5 General Information Brain child of Brain child of W. Daniel Hillis W. Daniel Hillis Lewis W. TuckerLewis W. Tucker

Founded Thinking Machines CorporationFounded Thinking Machines Corporationin the 1980’sin the 1980’s

CM-5 was last in a line of successors to theCM-5 was last in a line of successors to theoriginal CM-1 Connection Machineoriginal CM-1 Connection Machine

CM-5 Connection MachineCM-5 Connection MachineHardware OverviewHardware Overview

32-1638432-16384 processing nodes each of which processing nodes each of which contain a 32 MHz SPARC RISC processorcontain a 32 MHz SPARC RISC processor

32 MB32 MB of distributed memory of distributed memory

although the size may vary according to although the size may vary according to customer specificationscustomer specifications

128 Mflops128 Mflops (per processing node) yielding a (per processing node) yielding a total performance of 1Teraflops. total performance of 1Teraflops.

Tera=2^40 Tera=2^40 or roughly 10^12or roughly 10^12

Processing Node vs. Processing Node vs. ProcessorProcessor

Processing Node not a single processor but Processing Node not a single processor but a set a set of 5 chipsof 5 chips

Single 32 MHz SPARC RISC processor with Single 32 MHz SPARC RISC processor with

4 separate vector units capable of 4 separate vector units capable of performing 64 bit floating point and performing 64 bit floating point and integer integer arithmeticarithmetic

Diagram of Processing NodeDiagram of Processing Node

CM-5 Operating SystemCM-5 Operating System

CM-5 runs the CMOST OSCM-5 runs the CMOST OS

enhanced version of the UNIX OSenhanced version of the UNIX OS

Each processing node contains a Each processing node contains a microkernal of the OSmicrokernal of the OS

CM-5 MIMD or SIMD CM-5 MIMD or SIMD Machine?Machine?

Referred to as synchronized MIMD Referred to as synchronized MIMD machinemachine

somewhere between MIMD and SIMDsomewhere between MIMD and SIMD

best aspects of both types of best aspects of both types of machinesmachines

CM-5 Batch Processing or CM-5 Batch Processing or Timesharing?Timesharing?

CM-5 allows both Batch processing and CM-5 allows both Batch processing and TimesharingTimesharing

Timesharing is provided by dividing Timesharing is provided by dividing processing processing nodes into a partition nodes into a partition controlled by partition controlled by partition managermanager

Protection is enforced by hardware so that Protection is enforced by hardware so that one one partition cannot interfere with partition cannot interfere with anotheranother

Interconnection Network(s) Interconnection Network(s) What?What?

CM-5 has not one but three overlapping CM-5 has not one but three overlapping interconnection networksinterconnection networks

Data NetworkData Network

Control NetworkControl Network

Diagnostic NetworkDiagnostic Network

3 Overlapping 3 Overlapping Interconnection NetworksInterconnection Networks

CM-5 Data NetworkCM-5 Data Network

Supports simultaneous sending of Supports simultaneous sending of messages messages between processing nodesbetween processing nodes

Solves several problems:Solves several problems:

balancing message loads in networkbalancing message loads in network

““fetch-deadlock problem”fetch-deadlock problem”

timesharing a parallel computertimesharing a parallel computer

CM-5 Data NetworkCM-5 Data Network

Binary fat tree

CM-5 Data Network (cont.)CM-5 Data Network (cont.)

Messages are passed between processing Messages are passed between processing nodes using the least common nodes using the least common

ancestorancestor

Increasing bandwidth at each level upIncreasing bandwidth at each level up

Avoids “bottlenecks” at the root nodeAvoids “bottlenecks” at the root node

CM-5 Control NetworkCM-5 Control Network

Designed a simple treeDesigned a simple tree

Provides synchronization so as to allow Provides synchronization so as to allow CM-5 to CM-5 to operate like SIMD computeroperate like SIMD computer

In general control network provides for:In general control network provides for:

fast broadcasting of datafast broadcasting of data

barrier synchronizationbarrier synchronization

parallel prefix/postfix scan operationsparallel prefix/postfix scan operations

CM-5 Diagnostic NetworkCM-5 Diagnostic NetworkOrganized as incomplete binary treeOrganized as incomplete binary tree

Able to map-out or ignore parts of the tree Able to map-out or ignore parts of the tree that that are faultyare faulty

Able to select and access groups of system Able to select and access groups of system chips chips in parallel including:in parallel including:

single chipsingle chip

single type of chipsingle type of chip

chips within a user partitionchips within a user partition

chips associated within portion of chips associated within portion of the the system such as board, cabinet, system such as board, cabinet, etc.etc.

CM-5 Diagnostic Network CM-5 Diagnostic Network DiagramDiagram

ReferencesReferences

““The Network Architecture of the Connection The Network Architecture of the Connection Machine CM-5”, Thinking Machines Machine CM-5”, Thinking Machines Corporation February 7, 1996Corporation February 7, 1996

Hillis, Daniel and Tucker, Lewis “The CM-5 Hillis, Daniel and Tucker, Lewis “The CM-5 Connection Machine: A Scalable Connection Machine: A Scalable Supercomputer”Supercomputer”

Communications of the ACM, November 1993Communications of the ACM, November 1993

Volume 36, Number 11Volume 36, Number 11