A memory controller, system, and methods are disclosed. The system comprises a memory controller interconnected to a plurality of memory chips. Each memory chip stores data at a plurality of locations. The memory controller performs a sparing transaction comprising reading data from a given location of one or more of the memory chips including a first memory chip, writing the data to a given location of one or more of the memory chips including a second memory chip, wherein during writing, data from the first memory chip is written to the second memory chip, and allowing additional memory transactions directed to the memory chips between the start of reading and the end of writing unless the additional memory transaction is targeted to the given location. In a further embodiment, the sparing transaction comprises correcting errors in the data before writing the data.