Using all cores in parallel computing toolbox

I want to use all the core present in my pc. I have used matlabpool('open',core number) command at the starting of the program and matlabpool('close') at the end. But it took longer time than single core job. I'm using R2009a version. please help.

Answer 1

[Matt J]

You can open the Task Manager and view how many threads are crunching under the Performance tab. If all available threads show activity, then it could simply be that running in parallel is sub-optimal compared to running serially. This can happen, for example, if the size of the task is small compared to the overhead of setting up parallel workers and communicating data to them.