{"title":"Portability of performance with the BSPLib communications library","authors":"Jonathan M. D. Hill, S. Donaldson, D. Skillicorn","doi":"10.1109/MPPM.1997.715959","DOIUrl":"https://doi.org/10.1109/MPPM.1997.715959","url":null,"abstract":"The BSP cost model makes a new level of power available for designing parallel algorithms. First, it models the actual behaviour of today's parallel computers, and so can be used to choose appropriate algorithms without completely implementing them. Second, it becomes possible to characterise the range of architecture performance over which a particular algorithm is the best choice. This provides the foundations for developing software that is both portable at the source code level, and in its expectation of performance. We illustrate this by comparing three possible implementations of broadcast, and show that a two-phase broadcast algorithm outperforms other techniques whenever the size of the data is large relative to the cost of synchronisation, and that broadcasting using trees is never a good technique (despite its continued popularity). We carry out a similar analysis for samplesort, and show that samplesort cannot perform well on networks of workstations unless the network bandwidth exceeds a certain threshold.","PeriodicalId":217385,"journal":{"name":"Proceedings. Third Working Conference on Massively Parallel Programming Models (Cat. No.97TB100228)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130432568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Potential parallelism in iteration methods","authors":"T. Rauber, G. Runger","doi":"10.1109/MPPM.1997.715964","DOIUrl":"https://doi.org/10.1109/MPPM.1997.715964","url":null,"abstract":"The execution of iteration methods, including iteration methods for time-dependent differential equations, is one of the most time-consuming tasks in scientific computing, especially when large systems have to be solved, large time scales have to be computed or solutions of high quality are required. To decrease the computation time, parallel machines can be used but a detailed analysis of the potential parallelism is needed for an efficient implementation as data dependencies can strongly limit the performance. This article describes and compares the potential parallelism of various iterative solution methods for linear and non-linear equation systems and ordinary differential equations. Methods that have been especially designed for parallel execution as well as parallel implementations of modern efficient sequential solution methods are considered.","PeriodicalId":217385,"journal":{"name":"Proceedings. Third Working Conference on Massively Parallel Programming Models (Cat. No.97TB100228)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124419349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}