AMD’s newly launched Radeon RX 6700 XT has a decent hash rate of 47 MH/s, according to coreteks. This is, of course, an initial assessment and might change with newer drivers. Considering the mining capabilities of the rest of the Navi family, this sounds about right.
You’ve got the Radeon RX 5700 XT which manages a bit over 50 MH/s on account of its wider bus and external bandwidth. Although the Infinity Cache on the 6700 XT improves the cache hit-rates in gaming, especially at 1080p and 1440p, it’s redundant when it comes to mining.
The Radeon RX 6900 XT scores just over 60 MH/s in Ether which is roughly the same as NVIDIA’s RTX 3060 Ti. With the combination of a wider bus and a massive compute power, the Ampere lineup is truly ideal for mining. If you scale down the clocks on the RX 6900 XT to 5700 XT levels, the two GPUs will pretty much spit out the same hash rate. The limited bandwidth of the Radeon RX 6000 series is one of the primary factors behind the luke-warm mining performance.