Techniques are described for determining data movements. Gradient sets are determined for storage tiers. Each gradient set is associated with one of the storage tiers and includes at least one gradient. Based on the gradient sets, a donor tier and a first set of one or more receiving tiers are selected from the plurality of storage tiers. A first data portion having data currently stored on at least one physical device of the donor tier is selected. In accordance with data movement criteria, a second data portion included in a receiving tier of the first set is selected. Selecting the second data portion includes modeling a first data movement including moving the first data portion from the donor tier to the receiving tier. The first data movement may be included in a recommended list and may be performed by a data storage optimizer.