Jenkins - maximum number of concurrent jobs

The maximum number of Jenkins jobs is dependent upon what you set as the limits in the master and slaves. Usually, we limit by the number of cores, but your mileage may vary depending upon available memory, disk speed, availability of SSD, and overlap of source code.

For the master, this is set in Manage Jenkins > Configure System > # of executors

For the slaves (nodes), it is set in Manage Jenkins > Nodes > (each node) > Configure > # of executors

It's completely dependent on your hardware. If you run a single Jenkins instance with on build slaves, you can define how many concurrent build executors you want on the main configuration page at [your Jenkins URL]/configure - I've had success setting up 2 executors per CPU core available, but that will depend on what your builds do and how much CPU they need to consume.

If you also have remote build slaves, you can set up multiple executors on those as well. Your maximum number of concurrent jobs will be (executors on master) + (number of remote slaves) * (executors per slave).