1 / 8

CS 470/570 Lecture 4

CS 470/570 Lecture 4. Performance measures Interconnection networks Cache coherence Parallel Software Parallel Program design Example Problems. Performance Measures. Speedup T serial /T parallel Efficiency Speedup/number of processors Amdahl’s law Scalable. Interconnection Networks.

uriel-oneil
Download Presentation

CS 470/570 Lecture 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CS 470/570 Lecture 4 • Performance measures • Interconnection networks • Cache coherence • Parallel Software • Parallel Program design • Example Problems

  2. Performance Measures • Speedup • Tserial/Tparallel • Efficiency • Speedup/number of processors • Amdahl’s law • Scalable

  3. Interconnection Networks • Bus • Crossbar • Fully connected • Hypercube • Omega • Latency • Bandwidth

  4. Cache Coherence • Snooping cache coherence • Directory based cache coherence

  5. Parallel Software • Nondeterminism • Race conditions • Critical section • Mutual exclusion • Thread Safe

  6. Parallel Program Design • Partitioning • Communication • Aggregation

  7. Example Problems • 1. Draw a 4X4 crossbar switch. • 2. Draw a 4X4 Omega network • 3. Suppose there are 16 processors connected in a 4 dimensional hypercube. • a. How many direct connections to other processors does each processor have? • b. What is the minimum number of links that will have to be traversed to send data from processor 3 to processor 12?

  8. Example Problems • 4. Suppose you have a machine with 4 cores that uses snooping cache coherence. Core 0 reads from address 10,000, core 3 reads from address 10,000. Core 3 writes to address 10,000. How does Core 0 know its copy of the contents of address 10,000 is out of date. • 5. On a 4X4 Omega network can the following source destination requests be satisfied at the same time. (0,0), (3,1), (1,2), (2,3) • 6. How many switches are in an 8X8 crossbar? • 7. How many switches are on an 8X8 Omega network?

More Related