Patent ID: 7328308

Claim:
A data writing method for an RAID performed at a write cycle including a plurality of clocks, and cooperating with a first disk, a second disk, a third disk, and a memory module for storing a first data with a first segmented data and a second segmented data, a second data with a third segmented data and a fourth segmented data, and a first checking data, the third segmented data is stored in the first disk, and the first checking data is stored in the memory module, the writing method comprising: writing the fourth segmented data into the second disk during a first clock; reading the third segment data stored in the first disk during the first clock; writing the first checking data into the third disk during the first clock; calculating the second checking data in accordance with the third segmented data and the fourth segmented data during a second clock; and storing the second checking data into the memory module during the second clock.