Even Work Load: Invoicing of 100,000 single line Sales Orders. Bundle size used for this test is 1,000.
Uneven workload: Invoicing of 1000 Sales Orders and the number of lines for the sales orders vary between 1 and 500. Bundle size used is 100.
Very large number of work items: Since I wanted to use over a million work items for this test, instead of using the Sales Order invoicing, used a workload that completes much faster. (Check status of few different things and update my work item table accordingly). Used 2 Million work items for this test. The bellow metric shows when you create a very large number of work items, neither ‘top picking’ nor creating individual task will scale.
Depending on the nature of the workload and amount of work that needs to done on a regular basis you can decide a technique that suits your need the best.