introduction Flashcards
What does SISD stand for?
Single instruction, single data stream
A single processor executes a single instruction stream to operate on data stored in a single memory.
What characterizes SIMD stream?
A single machine instruction controls simultaneous execution of multiple processing elements on a lockstep basis
Vector and array processors fall into this category.
What does MISD stand for?
Multiple instruction, single data stream
A sequence of data is transmitted to a set of processors, each executing a different instruction sequence. Not commercially implemented.
What defines MIMD stream?
A set of processors simultaneously execute different instruction sequences on different data sets
SMPs, clusters, and NUMA systems fit this category.
What is a Symmetric Multiprocessor (SMP)?
A system where multiple processors share a common memory and are connected through a bus.
List three attractive features of bus organization.
- Simplicity
- Flexibility
- Reliability
What is a main drawback of bus organization?
Performance is limited by bus cycle time
All memory references pass through the common bus.
What is cache coherence?
A mechanism to maintain consistency among caches in a multiprocessor system.
What are the two categories of cache coherence protocols?
- Directory protocols
- Snoopy protocols
What does MESI stand for in cache protocols?
Modified, Exclusive, Shared, Invalid
What does multithreading allow for?
A high degree of instruction-level parallelism without increasing circuit complexity or power consumption.
Define implicit multithreading.
Concurrent execution of multiple threads extracted from a single sequential program.
What is a cluster in computing?
A group of interconnected whole computers working together as a unified computing resource.
List two approaches to clustering methods.
- Highly available clusters
- Fault tolerant clusters
What is a primary advantage of CC-NUMA systems?
Can deliver effective performance at higher levels of parallelism than SMP without requiring major software changes.
What is the main motivation for using cloud computing?
Cost efficiency and scalability.
What is the NIST cloud computing reference architecture focused on?
The requirements of ‘what’ cloud services provide, not a ‘how to’ design solution.
Fill in the blank: A _____ cloud infrastructure is implemented within the internal IT environment of the organization.
private
True or False: Nonuniform memory access (NUMA) means all processors access memory at the same speed.
False
What does the term ‘failover’ refer to in clustering?
Switching applications and data resources over from a failed system to an alternative system in the cluster.
What are the advantages of chip multiprocessing?
- Effective use of available logic area on a chip
- Handles separate threads
