How many MATLAB workers can I open on my client machine?

I just bought a Dell Precision T7600. The CPU specification is as follows:

Dual Eight Core XEON (E5-2687W, 3.1GHz, 20M, 8.0 GT/s, Turbo+)

If I do Windows Task Managers, under Performance/CPU Usage History, I see two rows, each with 16 columns. So 32 columns in total.

I know Parallel Computing Toolbox allows at most 12 workers to be open. I'm considering getting MATLAB Distributed Compusting Server.

So my question is: Can I open 32 workers with my hardware? If yes, I also buy the 32-worker version of MDCS...

Thanks!

Answer 1

[Walter Roberson]

Dual eight-core implies 16 total cores. If you are seeing 32 columns in total, it might indicate that you have hyperthreading turned on.

If you do have hyperthreading turned on, then it is allowed to create one worker for each (thread or hyperthread), which would be a total of 32.

You should be concerned, however, about whether you will get any benefit from turning on hyperthreads on your machine. There are computation patterns in which they help, but unless your computation patterns happens to include pauses (waiting for I/O for example) the your pure computation between the two hyperthreads per core would compete with each other, lowering performance. It is not uncommon to get better overall performance with hyperthreads turned off.

Answer 2

[Edric Ellis]

Please note that in R2014a the limit on the number of local workers was removed. See the release notes.