The maximum number of iterations to use for each customer sample is configurable using the Optimize|AlgorithmTuning|MaxIterationsPerCustomerSample property. Check both the session level advanced settings and the configuration properties.
To analyze the customer sample iteration behavior, search in the Contact Optimization log for the string
Iteration:. This log entry is followed by a number, indicating which iteration it is. Each chunk starts at iteration 1 and counts up. It helps to see what is going on if you get a count of each iteration number in the log, and use the results to construct a histogram.
Another major factor in performance is the number of unprocessable customers. If the value of the Optimize|AlgorithmTuning|MaxAlternativesPerCustomerEvaluated property is a large number (over 100 or so), the time penalty is high whenever a customer is unprocessable.
In Contact Optimization version 7.5.3 and later, there is more detailed logging to show the minimum, maximum, and average number of alternatives that are evaluated for each customer sample.