One embodiment facilitates global data placement in a storage device. The system receives a request to write first data. The system selects one of a plurality of physical media of the storage device to which to directly write the first data, based on a frequency of access, a block size, and a latency requirement of the first data, wherein the plurality of physical media includes a fast cache medium, a solid state drive, and a hard disk drive. In response to determining that the frequency of access of the first data is greater than a predetermined threshold, or in response to determining that the block size associated with the first data is not greater than a predetermined size and determining that the first data is an update to existing data, the system selects the fast cache medium. The system writes the first data to the selected one physical medium.