Controlling Multi-processing in MATLAB
in [Matlab]
|
From: Jonathan on 30 Jul 2010 12:47 Hi Everyone, One of the best things about a multi-core processor for my work is the ability to run simulations and leaving a core free for word processing. However, I've found in MATLAB 2009b and 2010a that MATLAB automatically uses multi-core and it would seem the majority of my code is parallelize and thus I never seem to have a free core during simulations. Long story short: how do I turn off multi-processing or better, limit the number of cores MATLAB will use during simulation? Thanks.
From: John D'Errico on 30 Jul 2010 13:12 "Jonathan " <jonathan.ethier(a)crc.gc.ca> wrote in message <i2uvm8$7iv$1(a)fred.mathworks.com>... > Hi Everyone, > > One of the best things about a multi-core processor for my work is the ability to run simulations and leaving a core free for word processing. However, I've found in MATLAB 2009b and 2010a that MATLAB automatically uses multi-core and it would seem the majority of my code is parallelize and thus I never seem to have a free core during simulations. > > Long story short: how do I turn off multi-processing or better, limit the number of cores MATLAB will use during simulation? > Why are people never happy? Either their code does not use parallel processing enough, so is too slow, or it uses too much. Long story short, use a better OS. Or get a machine with more cores and hyper-threading. Or get a cheap laptop that you use on the side to surf the web, do e-mail, and word processing on. John
From: Matt J on 30 Jul 2010 13:43 "Jonathan " <jonathan.ethier(a)crc.gc.ca> wrote in message <i2uvm8$7iv$1(a)fred.mathworks.com>... > Hi Everyone, > > One of the best things about a multi-core processor for my work is the ability to run simulations and leaving a core free for word processing. However, I've found in MATLAB 2009b and 2010a that MATLAB automatically uses multi-core and it would seem the majority of my code is parallelize and thus I never seem to have a free core during simulations. ================ Is that really true? If MATLAB always parallelizes computation, why buy the Parallel Computing Toolbox?
From: Jonathan on 30 Jul 2010 14:25 "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <i2v154$an2$1(a)fred.mathworks.com>... > "Jonathan " <jonathan.ethier(a)crc.gc.ca> wrote in message <i2uvm8$7iv$1(a)fred.mathworks.com>... > > Hi Everyone, > > > > One of the best things about a multi-core processor for my work is the ability to run simulations and leaving a core free for word processing. However, I've found in MATLAB 2009b and 2010a that MATLAB automatically uses multi-core and it would seem the majority of my code is parallelize and thus I never seem to have a free core during simulations. > > > > Long story short: how do I turn off multi-processing or better, limit the number of cores MATLAB will use during simulation? > > > > Why are people never happy? Either their code does not > use parallel processing enough, so is too slow, or it uses > too much. > > Long story short, use a better OS. Or get a machine with > more cores and hyper-threading. Or get a cheap laptop > that you use on the side to surf the web, do e-mail, and > word processing on. > > John I'm quite happy. I'm simply asking if there is a setting to control the multi-processing. It's not too much to ask to have control over things. If you don't have anything productive to add to the conversation, I suggest you don't post. Further to that point, your comments are inane. I've tried my code on a 2-core, 4-core and 8-core machine and it maxes out to 100% cpu usage every time. The solution is not to purchase an additional machine - that's simply wasteful and without sense. The solution is to have a simple checkbox that you click and say yes/no to parallel usage.
From: Bruno Luong on 30 Jul 2010 14:57
"Jonathan " <jonathan.ethier(a)crc.gc.ca> wrote in message <i2uvm8$7iv$1(a)fred.mathworks.com>... > Hi Everyone, > > One of the best things about a multi-core processor for my work is the ability to run simulations and leaving a core free for word processing. However, I've found in MATLAB 2009b and 2010a that MATLAB automatically uses multi-core and it would seem the majority of my code is parallelize and thus I never seem to have a free core during simulations. > > Long story short: how do I turn off multi-processing or better, limit the number of cores MATLAB will use during simulation? > > Thanks. Start your matlab session with -singleCompThread option. It is no longer possible to tune the number of threads within the session. Bruno |