A host interface controller with improved boot up efficiency, which uses a buffer mode setting register to set the operation mode of a first and a second buffer set provided within the host interface controller. When a cache memory of a central processing unit (CPU) at the host side has not started up, the first and second buffer sets operate in a cache memory mode to respond to read requests that the CPU repeatedly issues for data of specific addresses of the storage device. When the cache memory has started up, the first buffer set and the second buffer set operate in a ping-pong buffer mode to respond to read requests that the CPU issues for data of sequential addresses of the storage device.