Computer architecture multi processor
- 2. Outline: 1. Flynn's taxonomy 2. Multi processor Multiple cpu with shared memory UMA NUMA 3. Multi computer Tightly Coupled Systems Interconnection
- 3. Flynn's taxonomy: is a classification of computer architectures, proposed by Michael J. Flynn in 1966 The classification system has stuck, and has been used as a tool in design of modern processors and their functionalities. Since the rise of multiprocessing central processing units (CPUs), a multiprogramming context has evolved as an extension of the classification system. 1. Flynn's taxonomy
- 4. Flynn’s Taxonomy uses two basic concepts: Parallelism in instruction stream, and parallelism in data stream. Any CPU system has (n) program counter(pc), so there are (n) “instruction stream” that can execute in parallel. A data stream can be used as a sequence of data, and there exist 4 possible combinations.
- 5. 1.SISD(Single Instruction Single Data) A processor that can only do one job at a time from start to finish.
- 6. 2. SIMD(Single Instruction Multiple Data) controls the simultaneous execution of a number of processing elements, so that each instruction is executed on a different set of data by the different processors.
- 7. 2. SIMD(Single Instruction Multiple Data)
- 8. 3. MISD(Multiple instructions single data) A sequence of data is transmitted to a set of processors, each of which executes a different instruction sequence This structure is not commercially implemented.
- 9. 4. MIMD(Multiple instruction Multiple Data) 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.
- 10. 4. MIMD(Multiple instruction Multiple Data)
- 11. 2-Multiprocessor System: Definition A computer system in which two or more CPUs share full access to a common RAM .
- 12. Shared memory parallel computers vary widely, but generally have in common the ability for all processors to access all memory as global address space. Multiple processors can operate independently but share the same memory resources. Changes in a memory location effected by one processor are visible to all other processors. Historically, shared memory machines have been classified as UMA and NUMA, based on memory access times. Shared Memory
- 13. . . . interconnection network . . . processor 1 cache processor 2 cache processor N cache memory 1 memory M memory 2
- 14. 1. Uniform Memory Access (UMA) Uniform memory access (UMA) is a shared memory architecture used in parallel computers. All the processors in the UMA model share the physical memory uniformly. The UMA model is suitable for general purpose and time sharing applications by multiple users.
- 16. 2. Non-Uniform Memory Access (NUMA) Non-uniform memory access (NUMA) is a computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory faster than non-local memory (memory local to another processor or memory shared between processors).
- 18. Definition: Architecture in which each processor has its own memory rather than multiple processors with shared memory. PC multi-core, although it looks similar, it will not have multiple computers because multiple cores share a common memory 3.Multi computer:
- 19. 3. Multi computer Definition: • Are tightly-coupled CPUs that do not share memory (each one has its Memory) • These systems are also known by a variety of other names, cluster computers and COWS (Cluster of Workstations).
- 20. Tightly Coupled Systems Tightly coupled multiprocessor systems contain multiple CPUs that are connected at the bus level. These CPUs may have access to a central shared memory ( UMA), or may participate in a memory hierarchy with both local and shared memory (SM)(NUMA). Both ranges of processors had their own onboard cache but provided access to shared memory; the Xeon processors via a common pipe and the Opteron processors via independent pathways to the system RAM
- 21. MULTICOMPUTER HARDWARE Interconnection Topologies: An interconnection network in a parallel machine transfers information from any source node to any desired destination node . The network is composed of links and switches, which helps to send the information from the source node to the destination node Single Switch RING GRID Double Torus CUBE 4D Hypercube
- 22. Ring This is one of the simplest ways of connecting nodes with each other. The nodes are connected with each other to form a ring. For a node to communicate with some other node, it has to send the messages to its neighbor. Therefore, the data message passes through a series of other nodes before reaching the destination. This involves increased latency in the system.
- 23. Mesh network In a mesh network, multiple nodes are connected with each other. Each node in the network is connected to every other node in the network. This arrangement allows proper communication of the data between the nodes. But, there are a lot of communication overheads due to the increased number of node connections.
- 24. Hypercube This topology consists of connections of the nodes to form cubes. The nodes are also connected to the nodes on the other cubes.
- 25. Multicomputer Multiprocessor 1.A multiprocessor system is simply a computer that has more than one CPU on its motherboard. 2. Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. 3. Multiprocessors have a single physical address space (memory) shared by all the CPUs 4. A multiprocessor would run slower, because it would be in ONE computer. 5. A multi-processor is a single system with multiple CPU' 1.A computer made up of several computers. similar to parallel computing. 2. Distributed computing deals with hardware and software systems containing more than one processing element, multiple programs, running under a loosely or tightly controlled regime. 3. multicomputer have one physical address space per CPU. 4. It can run faster 5. A multi-computer is multiple computers, each of which can have multiple processors. Used for true parallel processing