Provided are an apparatus, computer program product, and method to perform cache operations in a solid state drive. A cache memory determines whether data for a requested storage address in a primary storage namespace received from a host system is stored at an address in the cache memory namespace to which the requested storage address maps according to a cache mapping scheme. Multiple of the storage addresses in the primary storage map to one address in the cache memory namespace. The cache memory returns to the host system the data at the requested address stored in the cache memory namespace in response to determining that the data for the requested storage address is stored in the cache memory namespace.