Data storage device with improved read performance and operating method thereof

An operating method of a data storage device which includes a nonvolatile memory apparatus having a plurality of groups, each including one or more planes, the groups being operable as respective interleaving units, the operating method comprising the steps of:

• receiving a read command;
• checking whether a current read group including a read region of a current read command and a previous read group including a read region of a previous read command completely or partially overlap and whether the read region of the current read command extends over two or more groups;
• and
• controlling the nonvolatile memory apparatus to perform cache read or interleaving read on the current read group based on the checking result.

An operating method of a controller, the operating method comprising:

• controlling a nonvolatile memory device to perform a cache read operation on planes disposed over two or more of plural groups in the nonvolatile memory device;
• and
• controlling the nonvolatile memory device to perform, in response to a current read command, the cache read operation on planes disposed in a current group among the plural groups when a previous group of a previous read command and the current group at least partially overlap in units of planes,
• wherein an interleaving read operation is performed on one or more planes disposed within each of the plural groups, and
• wherein the interleaving read operation is not performed on the planes disposed over two or more among the plural groups.