Apparatus and method for managing a non-volatile memory (NVM) such as a flash memory in a solid-state drive (SSD). In some embodiments, the NVM is arranged as a plurality of semiconductor memory dies coupled to a controller circuit using a plurality of channels. The controller circuit divides the plurality of dies into a succession of garbage collection units (GCUs). Each GCU is independently erasable and allocatable for storage of user data. The GCUs are staggered so that each GCU is formed from a different subset of the dies in the NVM. In further embodiments, the dies are arranged into NVM sets in accordance with the NVMe (Non-Volatile Memory Express) specification with each NVM set addressable by a different user for storage of data in a separate set of staggered GCUs.