An apparatus, system, and method are disclosed for deduplicating storage cache data. A storage cache partition table has at least one entry associating a specified storage address range with one or more specified storage partitions. A deduplication module creates an entry in the storage cache partition table wherein the specified storage partitions contain identical data to one another within the specified storage address range thus requiring only one copy of the identical data to be cached in a storage cache. A read module accepts a storage address within a storage partition of a storage subsystem, to locate an entry wherein the specified storage address range contains the storage address, and to determine whether the storage partition is among the one or more specified storage partitions if such an entry is found.