In Hyperopt, what happens if the parallelism parameter is set higher than the cluster cores?

When the parallelism parameter in Hyperopt is set higher than the number of cores available in the cluster, the correct outcome is that subtle delays occur as some trials have to wait for resources to become available. This happens because Hyperopt attempts to execute multiple trials in parallel, but when there are more trials than available cores, some trials cannot start immediately. They will be queued until resources are freed up by the completion of other trials currently running on the available cores.

This queuing process inherently introduces delays, as the system manages the allocation of core resources among the trials. As a result, while Hyperopt is designed to minimize the overall search time of the hyperparameter tuning process, setting parallelism too high can lead to inefficiencies instead of improved performance. Thus, rather than potentially leading to faster execution or improved accuracy, an overly ambitious parallelism setting can lead to a less efficient use of resources due to the waiting times involved.