With 150 MB/s: Serial ATA
Both Asus and MSI equip their KT400 boards with the Serial ATA controller PDC20376 from Promise. Although Serial ATA will not be replacing traditional ATA any time soon, the days of ribbon cables are definitely numbered. Among the advantages of Serial ATA, there's not only the higher data rate (up to 150 MB/s), but the thinner cable and the problem-free connector are easier to handle. Asus offers the more intelligent solution: the Serial ATA controller can support up to four drives. However, only two connections and a 40-pin connection are provided. The latter can be used for one or two IDE drives, or it can run two further Serial ATA drives via the adapter that comes in the packages.