Storage system having data storage lines with different data storage line sizes

A storage system, comprising:

• a data storage device, having a plurality of data storage lines;
• a tag storage device, having a plurality of address tags, each associated with one data storage line allocated in the data storage device;
• and
• a controller, coupled between the data storage device and the tag storage device, the controller arranged to set at least one first address tag and configure at least one first data storage line to serve as a first data storage line with a first data storage line size, and set at least one second address tag and configure at least one second data storage line to serve as a second data storage line with a second data storage line size, wherein the second data storage line size is different from the first data storage line size, a number of the at least one first address tag is equal to a number of the at least one first data storage line, and a number of the at least one second address tag is equal to a number of the at least one second data storage line.