Methods, systems, and devices for separate cores for media management of a memory sub-system are described. A controller of a memory sub-system can include a first processing core and a second processing core for a garbage collection procedure. The first processing core can perform a first set of one or more operations associated with a read process of a first stage of a garbage collection procedure for a plurality of transfer units of the memory sub-system. The second processing core can perform a second set of one or more operations associated with a write process of the first stage of the garbage collection procedure, where the second set of one or more operations are concurrent with the first set of one or more operations.