1. A system comprising: a cache device; and a controller communicatively coupled with a storage medium and with the cache device and configured to interface with a processor or a memory of a computer system, the controller being further configured to: receive a specified quantity of address references associated with a storage system; determine a spatial distribution of references to addresses of the storage system based at least in part on the received specified quantity of the address references, wherein to perform a determination of the spatial distribution, the controller is further configured to omit a random quantity of address references between previous determination of the spatial distribution and said determination of the spatial distribution; combine the determined spatial distribution with the previous determination of the spatial distribution into a spatial locality metric of the storage system; and output the spatial locality metric to use in caching data from the storage medium to the cache device.