Asus Z9PA-U8 - Manual (Page 51)

ASUS Z9PA-U8 2-31
3. Hard disk activity LED connector (4-pin HDLED1)
This LED connector is for the storage add-on card cable connected to
the SATA or SAS add-on card. The read or write activities of any device
connected to the SATA or SAS add-on card causes the front panel LED to
light up.
2. PSAS connectors (PIKE required)
SAS connector - PSAS connectors are for the SAS signal cables for SAS
hard disk drives that allows up to 6Gb/s of data transfer rate.
If you installed SAS hard disk drives, you can create a RAID 0, RAID 1, RAID
10, or RAID 5 configuration.
The actual data transfer rate depends on the speed of SAS hard disks installed.