Tiered caching and migration in differing granularities

For data processing in a distributed computing storage environment by a processor device, the distributed computing environment incorporating at least high-speed and lower-speed caches, and managed tiered levels of storage, groups of data segments and clumped hot ones of the data segments are migrated between the tiered levels of storage such that uniformly hot ones of the groups of data segments are migrated to use a Solid State Drive (SSD) portion of the tiered levels of storage; uniformly hot groups of data segments are determined using a first, largest granulated, heat map for a selected one of the group of the data segments; and a second heat map, which is smaller than the first and having the largest granularity of the first heat map, is used to determine the clumped hot groups.