A storage device of a DSN includes a plurality of memory devices, an interface, and a processing module. The storage device receives an encoded data slice of a set of encoded data slices, wherein a data segment is dispersed storage error encoded to produce the set of encoded data slices. The dispersed storage error encoding includes arranging the data segment into a data matrix of data blocks, generating an encoded data matrix from the data matrix and an encoding matrix, and arranging encoded data blocks of the encoded data matrix into the set of encoded data slices. The storage unit then divides the encoded data slice into encoded data slice partitions and generates a parity data partition therefrom. The storage device then stores the encoded data slice partitions and the parity data partition in separate memory devices.