Staggered garbage collection unit (gcu) allocation across dies

An apparatus comprising:

• a non-volatile memory (NVM) comprising a population of semiconductor memory dies to which are connected a number of parallel channels;
• a garbage collection unit (GCU) manager circuit configured to divide the plurality of dies into a succession of garbage collection units (GCUs) each independently erasable and allocatable for storage of user data, each GCU in the succession of GCUs formed from a different subset of the dies;
• and
• a data manager circuit configured to transfer data between the GCUs and at least one host device responsive to host access commands from the at least one host device.

A solid-state drive (SSD), comprising:

• a flash memory comprising a plurality of semiconductor memory dies;
• a plurality of channels interconnected to groups of the dies;
• and
• a controller circuit configured to direct a transfer of user data blocks between the dies and at least one host device, the controller circuit comprising a garbage collection unit (GCU) manager circuit configured to divide the plurality of dies into a succession of garbage collection units (GCUs) each independently erasable and allocatable for storage of user data, each GCU in the succession of GCUs formed from a different subset of the dies, the controller circuit further comprising a data manager circuit configured to write the user data blocks to the GCUs responsive to host access commands from the at least one host device.