AMD Radeon RX 6900 XT – Navi 21 XTX
This will be the fastest Big Navi model. It will feature 80 CUs, good for 5120 stream processors. The GPU has a 256-bit memory bus and will be paired with 16GB GDDR6 memory. Rumored clockspeeds include a 2040MHz Game clock and 2330MHz Boost.
One caveat is that this will be an AMD exclusive, at least for now. Quantity is said to be limited.
AMD Radeon RX 6800 XT – Navi 21 XT
One step down we have the Radeon RX 6800 XT, a model with 72 CUs and 4608 stream processors. It has a 256-bit bus with 16GB GDDR6 memory and the reference GPU clockspeeds are said to be 2015MHz for the Game clock, with a Boost of under 2250MHz.
AMD Radeon RX 6800 – Navi 21 XL
A further cut-down version of Navi 21 is the Radeon RX 6800. This variant packs 64 CUs, good for 4096 stream processors, and has the same 256-bit memory bus with 16GB GDDR6 memory. Expect a Game clock of 1815MHz and a Boost of 2105MHz.
AMD Radeon RX 6700 XT and 6700 – Navi 22 is for 2021
AMD's Radeon RX 6700 series is based on Navi 22, the company reportedly pulled the launch forward but you still shouldn't expect them anytime soon. The current launch schedule is reportedly January 2021. The Radeon RX 6700 XT is said to have a full Navi 22 GPU with 40 CUs and 2560 stream processors, coupled with a 192-bit memory bus and 12GB GDDR6.