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Re: OpenMP [message #30413 is a reply to message #30411]

Wed, 29 December 2010 14:48

dolik.rce
Messages: 1789
Registered: August 2008
Location: Czech Republic

Ultimate Contributor

281264 wrote on Wed, 29 December 2010 12:36

Any feedback on the performance/usability of OpenMP? Any piece of advice? Do you also use other tools?

OpenMP is IMHO a very handy tool if you are lazy and want to speed up some heavy computation. By lazy I mean you don't want to mess up with worker threads and all the related stuff. As long as there are some long for cycles which don't need to be processed in order, splitting them using OpenMP gives you great results for very little work. The only trouble is when you come to a point when you need to scale your app up and run it on cluster - then you have to rewrite it using other tools, most probably mpi.

I am using OpenMP for tedious tasks like counting distances between couples of atoms in atomic particles. The performance gain using omp is quite adequate. The thing I like most about OpenMP is that the code can be very simply compiled without it (basically just switching one flag to exclude the gomp library). That is great for debugging sometimes.

Honza

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