How many cores work in parallel in Mathematica?

Question

The Wolfram website claims that usually with its parallel function only 4 cores are used. If you need more than 4, you need to contact them and pay.

I have a machine with two quad-core hyperprocessors. When I run the Parallel commands, it launches 16 cores 2 x 4 x 2 (multiplier 2 for HT, I think). So it looks like 16 cores are being used, not 4. Fix? Perhaps my university license allows> 4 cores. I just wanted to check if I really use all available kernels.

Thanks.

Answer 1

The standard Mathematica license will have 2 cores, and then 4 sub-cores for each of the cores. So that would be 8 if your program used more than 1 normal kernel. Subkernels are what you use for parallel processing.

If you want to see how many subnuclei you are allowed to, please

(1) Contact Wolfram Support on [e-mail]

(2) Check your user portal account at user.wolfram.com. After entering the password, go to the "My Products and Services" section and select the copy of Mathematica that you are interested in looking at. On this product page, you will see an entry called “Processes” that tells you how many different processes you receive from your license.

You can use commands such as $ KernelCount to find out how many sub-cells are running.