Gigabyte has announced that it is now enabling 40Gb/s Thunderbolt 3 support on select motherboard that had 20Gb/s Thunderbolt 2 support via simple firmware update.
According to details, it appears that the Thunderbolt controllers on the Z170X-Gaming G1, Z170X-Gaming GT, and Z170X-Gaming 7 motherboards support Thunderbolt 3 but were previously limited to 20Gb/s due to lack of certification.
In addition to Thunderbolt 3 over traditional Thunderbolt/mini-DisplayPort connector, these motherboards also support Thunderbolt protocol over USB 3.1 Type-C at lower bandwidth, which should provide support for Thunderbolt-based docks that support USB Type-C.
In order to get the full support, all you need to do is update your BIOS to the latest one which can be found at Gigabyte's support site.
Source:
Gigabyte.com.