Power Requirement on TX2

We need to use 7 USB 3.0 devices by connecting them through the PCIe x4 port. Plus also a SATA SSD. If a 16.8 V Lipo is used to power the TX2, Can the carrier board supply the required current? (assuming I use all the 7 USB ports drawing maximum current)

I don’t know what the official answer would be, but my gut feeling is “no”. Does the PCIe card have any ability to supply via external power or secondary cable?