Described is an apparatus which comprises: a first encoder to encode data with a first error correction scheme to generate a set of codewords, each codeword of the set having a data portion and a corresponding parity portion, and each codeword of the set to be stored in a separate memory bank of a memory block; and a second encoder to encode the data portions of each codeword of the set with a second error correction scheme, the second encoder to generate a combined codeword having a data portion and a corresponding parity portion, wherein the corresponding parity portion of the combined codeword is to be stored in an additional memory bank of the memory block.