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![Page 1: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/1.jpg)
Introduction
Name: Jani Peusaari
Office: 6608
Contact:
Email: [email protected]
Reception hours: Tuesday 13-14
![Page 2: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/2.jpg)
Timetable
wk 1: Introduction, terms, other basic stuffwk 2: Complexity analysiswk 3: Abstract modelswk 4: Abstract models, architectureswk 5: Interconnections, embeddingwk 6: Communicationswk 7: Practical issues, Los grande
coding assignment
![Page 3: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/3.jpg)
Application areas
YOU TELL US
![Page 4: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/4.jpg)
Terms
• Task – Tehtävä– General description of a processing element
• Process – Prosessi– A process runs in some arbitrary computer
• Thread – Säie– ”Lightweight process”, threads run in some
arbitrary process
• Communication– Between tasks, processes, threads
![Page 5: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/5.jpg)
Terms
• Shared Memory – Jaettu muisti• Distributed Memory – Hajautetty muisti• Architecture
– Way to connect Processors to each other
• Problem size: n, N• Number of tasks: p, P• Memory: m, M• Time to complete certain operation: t, T
![Page 6: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/6.jpg)
Example 1
The job is to estimate how long it takes to count n numbers with p people, One person calculates n numbers in (n-1)tc. Let us presume, that there are eight persons and the numbers are easily divided among them. Transferring the results takes tw. How long it takes for n people if:
a) They are sitting in a circle b) They are sitting in 2 by 4 rows.
![Page 7: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/7.jpg)
![Page 8: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/8.jpg)
![Page 9: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/9.jpg)
Example 2
One person uses (n-1)tc to count n numbers. Is it possible that p persons solves the problem in less time than
(n-1)tc/p ?
Justify your answer !
![Page 10: Introduction](https://reader035.fdocuments.us/reader035/viewer/2022072015/56813021550346895d95a2c0/html5/thumbnails/10.jpg)
Example 3
What if the eight people from assignment number 1 calculate partial sums on the blackboard so that everyone can see the others results as soon as they are ready.
How long a time it takes now and how about assignment number 2?