A specification sheet has been leaked to the web which confirms that the Radeon RX 6900 XT Liquid Cooled (LC) is actually a separate SKU from the normal Radeon RX 6900 XT. The leaked sheet shows that the liquid cooled version will have a game clock of 2250 MHz (compared to 2015 MHz of the reference card) and the GDDR6 memory will operate at 18 Gbps (compared to the 16 Gbps of the refence card).
These upgrades will give the card a GPU memory bandwidth of 576 GB/s compared to the 512 GB/s on the reference. To support the higher clocks the Total Board Power (TDP) has been increased by 10% up to 330W compared to the 300W of the reference card. The Liquid Cooled edition of the RX 6900 XT will have an all-in-one, closed-loop liquid cooling solution, but will still draw power from the same dual 8-pin power connectors as the reference card.