Asus P9D-V - Manual (Page 46)

2-28 Chapter 2: Hardware information
5. Thermal sensor cable connectors (3-pin TR1)
This connector allows you to connect a Thermal sensor cable that is used for
temperature monitoring. Connect the Thermal sensor cable to the connector and place
its probe to the device that you want to check the temperature.
4. USB 3.0 connector (20-1 pin USB3_34)
These connectors allow you to connect a USB 3.0 module for additional USB 3.0 front
or rear panel ports. With an installed USB 3.0 module, you can enjoy all the benefits of
USB 3.0 including faster data transfer speeds of up to 5Gbps, faster charging time for
USB-chargeable devices, optimized power efficiency, and backward compatibility with
USB 2.0.