I'm guessing for eSATA, Kinda like a USB Hard Drive. only SATA.
The answer is on page 54 of the product guide:
The board is backward compatible with ATX12V power supplies.
If you use one of these (older style) power supplies you must connect power to either the SATA header or the Molex header to properly power a PCI-x video card.
If your power supply is the 'newer style' with a 2X4 pin power connector, you are all set.
Connecting Power Supply Cables
Figure 30 shows the location of the power connectors.
Failure to use an appropriate power supply and/or not connecting the 12 V
(Figure 30, A) power connector to the Desktop Board may result in damage to the
board or the system may not function properly.
The 2 x 12 pin main power connector (Figure 30, D) is backwards compatible with
ATX12V power supplies with 2 x 10 connectors. Use of the 1 x 4 auxiliary PCI Express
graphics power connector (Figure 30, C) or the SATA-style auxiliary power connector
(Figure 30, B) is required with ATX12V power supplies when using PCI Express
graphics cards that can consume up to 75 W.