In one aspect, data is stored in a solid state memory which includes first and second memory layers. A first assessment is executed to determine whether received data is hot data or cold data. Received data which is assessed as hot data during the first assessment is stored in the first memory layer, and received data which is first assessed as cold data during the first assessment is stored in the second memory layer. Further, a second assessment is executed to determine whether the data stored in the first memory layer is hot data or cold data. Data which is then assessed as cold data during the second assessment is migrated from the first memory layer to the second memory layer.