https://communities.sas.com/t5/SAS-Procedures/any-example-to-show-speed-enhancement-by-parallel-programming/m-p/53464#M14777 I seriously doubt that splitting the data on a CPU bound job is going to help. The DATA step is single-threaded; and you are tripling the number of steps and more than doubling the disk I/O.<BR /> <BR /> SAS already does a lot of multiprocessor optimization. I doubt that you would beat it with hand coding.<BR /> <BR /> Doc Muhlbaier<BR /> Duke Wed, 20 Apr 2011 00:55:32 GMT Doc_Duke 2011-04-20T00:55:32Z https://communities.sas.com/t5/SAS-Procedures/any-example-to-show-speed-enhancement-by-parallel-programming/m-p/53463#M14776 Folks,<BR /> <BR /> I am learning the parallel programming technique to take advantage of multi- processor computers.<BR /> <BR /> I understand that the speed of the code could be bounded by CPU or I/O.<BR /> I've read some article mentioning a rule of thumb that if the CPU time of the original code is more than 25% of the real time, the speed would be improved by parallel processing.<BR /> <BR /> So I picked a code of data step that CPU time is about 80% of the real time (17min vs. 22min). What I did was to split the data into two similar sized pieces. Then I ran the data step on both pieces in the way of parallel programming (buy using rsubmit/endrsubmit).<BR /> <BR /> The result was surprising that the new code cost me about 45min!<BR /> <BR /> From the log, I see each thread took about the same CPU time as before (15min and 16min) but much longer real time (31min and 47min) than the original 22min.<BR /> <BR /> The only reason I can think of is the I/O and network jam (the data step does a hash merge against data on server)<BR /> <BR /> My question is: who can give me some practical examples that take speed advantage of this kind of multi-thread parallel programming, in this rsubmit/endrsubmit way, on one multi-processor computer (like a core2duo)?<BR /> <BR /> Thanks,<BR /> Alex Tue, 19 Apr 2011 22:27:38 GMT https://communities.sas.com/t5/SAS-Procedures/any-example-to-show-speed-enhancement-by-parallel-programming/m-p/53463#M14776 tangyoulei 2011-04-19T22:27:38Z https://communities.sas.com/t5/SAS-Procedures/any-example-to-show-speed-enhancement-by-parallel-programming/m-p/53464#M14777 I seriously doubt that splitting the data on a CPU bound job is going to help. The DATA step is single-threaded; and you are tripling the number of steps and more than doubling the disk I/O.<BR /> <BR /> SAS already does a lot of multiprocessor optimization. I doubt that you would beat it with hand coding.<BR /> <BR /> Doc Muhlbaier<BR /> Duke Wed, 20 Apr 2011 00:55:32 GMT https://communities.sas.com/t5/SAS-Procedures/any-example-to-show-speed-enhancement-by-parallel-programming/m-p/53464#M14777 Doc_Duke 2011-04-20T00:55:32Z