Open all cores in Parpool

Hi all,

I am using R2014a on my server. It has 32 cores. But every time I use parpool it can only connected to 16 workers. This also happens when I use a 4 core laptop (can only connected to 2 workers).

How can I use all the 32 cores?

Answer 1

[Dasharath Gulvady]

I am guessing you have 16 physical cores and 32 virtual cores. "parpool" opens up same number of workers as your physical cores.

The performance of Parallel Computing Toolbox is better when the number of workers is same as the number of physical cores. However, you may set the number of workers to a different value by following one of the two options:

1) Go to Parallel Computing Options-> Manage Cluster Profiles-> local Click on Edit and change the value of ‘Number of workers to start on your local machine’ to 8

2) Type the following command in the MATLAB command window

parpool(32)

[Sean de Wolski]

However, it rarely makes sense to use more workers than physical cores since you're paying more communication overhead and the resources will still be tied up by the first 16 workers anyway.