Setting Concurrency Specification
The concurrency specification is a list of the number of threads on which the graph is run. To set the concurrency:
- Open thePreferenceswindow.
- Go to thecategory.
- Set the list in theConcurrency Specificationfield in the1,format, where:a-b:n
- 1is the serial run. Because the speedup is estimated with respect to a serial run of a graph, by default, all graphs are first run serially before running on multiple threads. The addition of 1 is merely symbolic and informational, as its omission has no effect on the list.
- ais the starting number of multiple threads.
- bis the ending number of multiple threads.
- nis the step size.
The default end value is the number of cores on the system and the default step size is a quarter of this value. The end value is always included in the list, even if it is not a direct multiple of the step size.
As an example, on a 32-core system, the default is
1,8-32:8
. This results in the list
1,8,16,24,32
, as shown below.

Other supported formats are
a,b,c
or only
a
if you want to see the speedup for only one set of threads.
You can also combine formats. The following shows some valid concurrency specifications:
- Range without a step size:16-64yields1,16,32,48,64
- Range with a step size:16-64:8yields1,16,24,32,40,48,56,64
- Single value:16yields1,16
- List of values:16,32,64yields1,16,32,64
- Mix of range and list:16-64,40,48,56yields1,16,32,40,48,56,64