Take it with a grain of salt, but a ChipHell poster claims AMD is working on two new consumer video card series. If the rumor is accurate, we can expect the 12nm Polaris 30 GPU in Q4 2018, a 7nm Vega 20 gaming GPU in Q1 2019 and 7nm Navi in the 2019/2020 timeframe.
This is the first time we hear about Polaris 30 and a Radeon RX version of Vega 20, will be interesting to see if this rumor is true.
The AMD Polaris 30 GPUs are completely unheard of and not even part of any roadmap we have seen so far. The Polaris 30 GPU is said to be the third iteration to the high-end Polaris line which initially shipped as Polaris 10 in 2016 followed by Polaris 20 in 2017. Polaris 30 based GPUs are said to use the latest 12nm FinFET process and deliver a 15% performance jump over Polaris 20 GPUs.