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Chapter 17 - 18. Hardwired vs Microprogrammed Control Multithreading Multicore Computers Summary of Parallel Organizations Recap of Course Final Exam: Next Thursday- Same time / same place. Hardwired Control. Hard Wired Control (State machine - Combinational Logic).
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Chapter 17 - 18 Hardwired vs Microprogrammed Control Multithreading Multicore Computers Summary of Parallel Organizations Recap of Course Final Exam: Next Thursday- Same time / same place
Hardwired Control Hard Wired Control (State machine - Combinational Logic)
Microprogrammed Control Micro-Control Memory Note: Assume we begin in State A Sequencer: Micro-Control Memory
Definitions of Threads and Processes • Process: • An instance of program running on computer • Thread: dispatchable unit of work within process • Includes processor context (which includes the program counter and stack pointer) and data area for stack • Threads execute sequentially, but are Interruptible • the processor can turn to another thread • Thread switch • Switching processor between threads within same process • Typically less costly than process switch
Implicit and Explicit Multithreading • Explicit Multithreading is Concurrently executing instructions from different explicit threads • Instructions are Interleaved from different threads on shared pipelines or executed in Parallel on separate pipelines • Implicit multithreading is concurrent execution of multiple threads extracted from a single sequential program • Implicit threads are defined statically by the compiler or dynamically by hardware
Intel x86 Multicore OrganizationCore i7 • Released November 2008 • Speculative pre-fetch for caches • Simultaneous multi-threading (SMT) • 4 SMT cores, each supporting 4 threads appears as 16 cores • On chip DDR3 memory controller • Three 8 byte channels (192 bits) giving 32GB/s • QuickPath Interconnection • Cache coherent point-to-point link • High speed communications between processor chips • 6.4G transfers per second, 16 bits per transfer • Total bandwidth 25.6GB/s
Intel Core i7 Block Diagram .3 ns/B !
Parallel Processor Architecture Summary Very Tightly Coupled Tightly Coupled Moderately Coupled
MultiCore Organization(Very tightly Coupled or Single Processor)
Symmetric Multiprocessor (SMP) Organization(Tightly Coupled)
Non-Uniform Memory Access (NUMA) Organization(Moderately Coupled)