The document discusses multiprocessing and thread-level parallelism. It covers four categories of parallel architectures: SISD, SIMD, MISD, and MIMD. MIMDs offer flexibility as they can function as single-user multiprocessors, run many tasks simultaneously, or a combination. MIMDs also leverage existing processor designs through replication. Centralized shared-memory and distributed-memory multiprocessors are described along with communication architectures like distributed shared memory and message passing. Challenges with parallel processing include limited parallelism in programs and high latency of remote access.

1. Multiprocessors and Thread-Level Parallelism Introduction “ The blueprints for our UltraSPARC T2, the core design files and test suites, will be available to the open source community, via its most popular license: the GPL.” Sun President Jonathan Schwartz (2007)‏

2. Multiprocessing Reliance Factors A growing interest in servers and server performance A growth in data-intensive applications The insight that increasing performance on the desktop is less important (outside of graphics, at least)‏ An improved understanding of how to use multiprocessors effectively, especially in server environments where there is significant natural thread-level parallelism The advantages of leveraging a design investment by replication rather than unique design — all multiprocessor designs provide such leverage

3. Taxonomy of Parallel Architectures Four Categories ( Flynn[1966] ): SISD: Single Instruction Stream, Single Data Stream SIMD: Single Instruction Stream, Multiple Data Stream MISD: Multiple Instruction Stream, Single Data Stream MIMD: Multiple Instruction Stream, Multiple Data Stream

4. Why Multiple Instruction, Multiple Data MIMDs offer flexibility. MIMDs can function as single-user multiprocessors, as multiprocessors running many tasks simultaneously, or as some combination of these functions. MIMDs can build on the cost-performance advantages of off-the-shelf processors. Multicore chips leverage the design investment in a single processor core by replicating it.

5. Centralized Shared-memory Multiprocessor

6. Distributed-memory Multiprocessor

7. Communication and Memory Architecture Distributed Shared-Memory (DSM)‏ Message-Passing Multiprocessors

8. Challenges of Parallel Processing Limited parallelism available in programs Large latency of remote access in a parallel processor

9. Thank you! Author: Prof. Sergio Takeo, Marcelo Arbore. Bibliography: Patterson, D. A.; Hennessy, J. L. Computer Architecture: A Quantitative Approach, 4 th Ed. Morgan Kaufmann Publishers. “ The blueprints for our UltraSPARC T2, the core design files and test suites, will be available to the open source community, via its most popular license: the GPL.” Sun President Jonathan Schwartz (2007)‏