Massively parallel processor array
Encyclopedia
A Massively Parallel Processor Array (MPPA) is a type of integrated circuit
which has a massively parallel
array of hundreds or thousands of CPU
s and RAM
memories. These processors pass work to one another through a reconfigurable
interconnect of channels
. By harnessing a large number of processors working in parallel, an MPPA chip can accomplish more demanding tasks than conventional chips. MPPAs are based on a software parallel programming model for developing high-performance embedded system
applications.
(Multiple Instruction streams, Multiple Data) architecture, with distributed memory
accessed locally, not shared globally. Each processor is strictly encapsulated, accessing only its own code and memory. Point-to-point communication between processors is directly realized in the configurable interconnect.
The MPPA's massive parallelism and its distributed memory MIMD architecture distinguishes it from multicore
and manycore architectures, which have fewer processors and an SMP
or other shared memory
architecture, mainly intended for general-purpose computing, and from GPGPU
s with SIMD
architectures, used for HPC
applications.
or workflow
, whose basic objects run in parallel, each on their own processor. Likewise, large data objects may be broken up and distributed into local memories with parallel access. Objects communicate over a parallel structure of dedicated channels. The objective is to maximize aggregate throughput while minimizing local latency, optimizing performance and efficiency. An MPPA's model of computation
is similar to a Kahn process network or Communicating sequential processes
(CSP).
s and hardware acceleration
of desktop computer
and server
applications, such as video compression, image processing
, medical imaging
, network processing, software defined radio and other compute-intensive streaming media applications, which otherwise would use FPGA, DSP
and/or ASIC
chips.
-architecture MPPAs, PicoChip MPPAs, IntellaSys MPPAs and ASOCS MPPAs.
The PARO-design system at the University of Erlangen-Nuremberg is another example, which targets mainly DSP
algorithms and image processing
. The advantage of PARO is retargetable compilation of a high-level description of an algorithm to a highly optimized ASIC
or reconfigurable architecture
efficiently.
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
which has a massively parallel
Massively parallel
Massively parallel is a description which appears in computer science, life sciences, medical diagnostics, and other fields.A massively parallel computer is a distributed memory computer system which consists of many individual nodes, each of which is essentially an independent computer in itself,...
array of hundreds or thousands of CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
s and RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...
memories. These processors pass work to one another through a reconfigurable
Reconfigurability
Reconfigurability denotes the Reconfigurable Computing capability of a system, so that its behavior can be changed by reconfiguration, i. e. by loading different configware code. This static reconfigurability distinguishes between reconfiguration time and run time...
interconnect of channels
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...
. By harnessing a large number of processors working in parallel, an MPPA chip can accomplish more demanding tasks than conventional chips. MPPAs are based on a software parallel programming model for developing high-performance embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
applications.
Architecture
MPPA is a MIMDMIMD
In computing, MIMD is a technique employed to achieve parallelism. Machines using MIMD have a number of processors that function asynchronously and independently. At any time, different processors may be executing different instructions on different pieces of data...
(Multiple Instruction streams, Multiple Data) architecture, with distributed memory
Distributed memory
In computer science, distributed memory refers to a multiple-processor computer system in which each processor has its own private memory. Computational tasks can only operate on local data, and if remote data is required, the computational task must communicate with one or more remote processors...
accessed locally, not shared globally. Each processor is strictly encapsulated, accessing only its own code and memory. Point-to-point communication between processors is directly realized in the configurable interconnect.
The MPPA's massive parallelism and its distributed memory MIMD architecture distinguishes it from multicore
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
and manycore architectures, which have fewer processors and an SMP
Symmetric multiprocessing
In computing, symmetric multiprocessing involves a multiprocessor computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture...
or other shared memory
Shared memory
In computing, shared memory is memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Depending on context, programs may run on a single processor or on multiple separate processors...
architecture, mainly intended for general-purpose computing, and from GPGPU
GPGPU
General-purpose computing on graphics processing units is the technique of using a GPU, which typically handles computation only for computer graphics, to perform computation in applications traditionally handled by the CPU...
s with SIMD
SIMD
Single instruction, multiple data , is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data simultaneously...
architectures, used for HPC
High-performance computing
High-performance computing uses supercomputers and computer clusters to solve advanced computation problems. Today, computer systems approaching the teraflops-region are counted as HPC-computers.-Overview:...
applications.
Programming
An MPPA application is developed by expressing it as a hierarchical block diagramBlock diagram
Block diagram is a diagram of a system, in which the principal parts or functions are represented by blocks connected by lines, that show the relationships of the blocks....
or workflow
Workflow
A workflow consists of a sequence of connected steps. It is a depiction of a sequence of operations, declared as work of a person, a group of persons, an organization of staff, or one or more simple or complex mechanisms. Workflow may be seen as any abstraction of real work...
, whose basic objects run in parallel, each on their own processor. Likewise, large data objects may be broken up and distributed into local memories with parallel access. Objects communicate over a parallel structure of dedicated channels. The objective is to maximize aggregate throughput while minimizing local latency, optimizing performance and efficiency. An MPPA's model of computation
Model of computation
In computability theory and computational complexity theory, a model of computation is the definition of the set of allowable operations used in computation and their respective costs...
is similar to a Kahn process network or Communicating sequential processes
Communicating sequential processes
In computer science, Communicating Sequential Processes is a formal language for describing patterns of interaction in concurrent systems. It is a member of the family of mathematical theories of concurrency known as process algebras, or process calculi...
(CSP).
Applications
MPPAs are used in high-performance embedded systemEmbedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s and hardware acceleration
Hardware acceleration
In computing, Hardware acceleration is the use of computer hardware to perform some function faster than is possible in software running on the general-purpose CPU...
of desktop computer
Desktop computer
A desktop computer is a personal computer in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lay flat on the desk, while modern towers stand upright...
and server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
applications, such as video compression, image processing
Image processing
In electrical engineering and computer science, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame; the output of image processing may be either an image or, a set of characteristics or parameters related to the image...
, medical imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
, network processing, software defined radio and other compute-intensive streaming media applications, which otherwise would use FPGA, DSP
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
and/or ASIC
ASIC
ASIC may refer to:* Application-specific integrated circuit, an integrated circuit developed for a particular use, as opposed to a customised general-purpose device.* ASIC programming language, a dialect of BASIC...
chips.
Examples
MPPAs include commercial devices from several companies such as: Nethra's AmbricAmbric
Ambric-architecture processors, are developed and marketed by a division of Nethra, a fabless semiconductor company based in Santa Clara, California. Nethra purchased the Ambric technology in early 2009. Ambric the company was founded in 2003 and the current team, all from the original startup,...
-architecture MPPAs, PicoChip MPPAs, IntellaSys MPPAs and ASOCS MPPAs.
The PARO-design system at the University of Erlangen-Nuremberg is another example, which targets mainly DSP
Digital signal processing
Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...
algorithms and image processing
Image processing
In electrical engineering and computer science, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame; the output of image processing may be either an image or, a set of characteristics or parameters related to the image...
. The advantage of PARO is retargetable compilation of a high-level description of an algorithm to a highly optimized ASIC
or reconfigurable architecture
efficiently.