> ## Documentation Index
> Fetch the complete documentation index at: https://docs.incredibuild.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Advanced Test Level Optimization

In the Test-level mode, Incredibuild for Unit Testing offers the ability to limit the number of cores that will participate in the distribution, by using the /testlevel=N command option. This setting should be used to optimize the distribution based on the following considerations:

* **Boot "lead" time** - each core will require a one-time booting of the test framework environment. The boot time may take as much as a minute, but after the boot process is completed, you will be able to run any number of tests consequently without any delays.

* **Number of available cores** – the number of available cores is dependent on your licensing and the actual number of cores that have idle CPUs.  

In general, you should strive to keep the N value as close as the number of available cores in your Incredibuild network, in a way that will minimize the impact of the boot "lead" time. Our support staff will help you calculate the expected available number of cores and with the optimization process.