$DefaultParallelKernels
✖
$DefaultParallelKernels
Details

- On a multicore computer, the list typically includes as many local kernels as there are cores, up to a limit defined by license availability.
- Additional configurations for kernels on remote machines can be made available with the Wolfram Lightweight Grid, WSTPServer and SSH connections.
- The value of $DefaultParallelKernels is remembered between sessions.
- When no kernels are running, LaunchKernels[] will launch the kernels given in $DefaultParallelKernels.
- $DefaultParallelKernels can be set by assigning a list of kernel configurations or via the Evaluation ▶ Parallel Kernel Configuration… menu item.
Examples
open allclose allBasic Examples (3)Summary of the most common use cases
The default value of $DefaultParallelKernels:

https://wolfram.com/xid/0bzsyjlafig04wwis-pcfbx7

When no kernels are running, LaunchKernels uses this list as the default to launch kernels:

https://wolfram.com/xid/0bzsyjlafig04wwis-dneh9o

Kernels can be specified using URL syntax:

https://wolfram.com/xid/0bzsyjlafig04wwis-zbzwo6


https://wolfram.com/xid/0bzsyjlafig04wwis-p46tso

Kernels can be specified using KernelConfiguration:

https://wolfram.com/xid/0bzsyjlafig04wwis-c8e0dt


https://wolfram.com/xid/0bzsyjlafig04wwis-43eyyy

Applications (2)Sample problems that can be solved with this function
Assignments to $DefaultParallelKernels are remembered between sessions:

https://wolfram.com/xid/0bzsyjlafig04wwis-u1qjt2

In a new session, the value is restored:

https://wolfram.com/xid/0bzsyjlafig04wwis-lhz1n6

https://wolfram.com/xid/0bzsyjlafig04wwis-09d3ic

Remove any persistent value by reverting $DefaultParallelKernels to its default:

https://wolfram.com/xid/0bzsyjlafig04wwis-h1cprw

Wolfram Research (2023), $DefaultParallelKernels, Wolfram Language function, https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html.
Text
Wolfram Research (2023), $DefaultParallelKernels, Wolfram Language function, https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html.
Wolfram Research (2023), $DefaultParallelKernels, Wolfram Language function, https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html.
CMS
Wolfram Language. 2023. "$DefaultParallelKernels." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html.
Wolfram Language. 2023. "$DefaultParallelKernels." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html.
APA
Wolfram Language. (2023). $DefaultParallelKernels. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html
Wolfram Language. (2023). $DefaultParallelKernels. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html
BibTeX
@misc{reference.wolfram_2025_$defaultparallelkernels, author="Wolfram Research", title="{$DefaultParallelKernels}", year="2023", howpublished="\url{https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html}", note=[Accessed: 09-July-2025
]}
BibLaTeX
@online{reference.wolfram_2025_$defaultparallelkernels, organization={Wolfram Research}, title={$DefaultParallelKernels}, year={2023}, url={https://reference.wolfram.com/language/ref/$DefaultParallelKernels.html}, note=[Accessed: 09-July-2025
]}