Asus Z9PE-D16 - Manual (Page 46)

2-28 Chapter 2: Hardware information
The actual data transfer rate depends on the speed of SATA hard disks installed.
2. SATA connector -- ISAS connectors
Supported by the Intel ® C602 PCH. ISAS 1-4 connectors can connect to serial
ATA 3Gb/s hard disk drives.