Storage device and method of operating the same

A storage device communicating with a host including a host memory, the storage device comprising:

• a semiconductor memory device including a plurality of non-volatile memory cells;
• and
• a device memory configured to store a priority table for determining a host performance booster (HPB) sub-region to be cached in the host memory,
• wherein the storage device is configured to update the priority table based on a read command received from the host and to transfer, to the host, a message recommending the HPB sub-region to be cached in the host memory based on the priority table.

A method of operating a storage device communicating with a host including a host memory, the method comprising:

• determining to deactivate any one of a plurality of host performance booster (HPB) regions cached in the host memory;
• selecting any one of the plurality of HPB regions based on validity rates of the plurality of HPB regions cached in the host memory;
• and
• transferring, to the host, a message recommending to deactivate the selected HPB region.

An operating method of a host performance booster (HPB) system, the operating method comprising:

• deactivating a currently activated higher group of map data, in which a number of invalid lower groups of map data is greater than a threshold;
• and
• activating a currently deactivated and valid lower group of map data having a highest priority among all lower groups of map data,
• wherein the priority increases whenever reading data related to a corresponding lower group of map data,
• wherein an increment of the priority is different depending on whether the corresponding lower group is activated or whether the corresponding lower group, which is activated, is valid.