AMD's GCN architecture has proven to be one of the most successful macro architectures of its time debuting with the Southern Islands micro-architecture (1st Generation GCN) and lives on, currently, with the Vega micro-architecture (5th Generation GCN). Navi, the upcoming next generation uArch from AMD in 2019 will constitute the 6th Generation GCN and will be the last and final breath of this overarching GCN series.

Navi will be the last GCN-based architecture, will be succeeded by brand new macro-architecture in 2020/2021 timeframe, execution of GCN successor being led by new RTG leadership

We were told that work had already started on the brand new major-architecture before Raja Koduri even left, but since we are hearing chatter about it then it means that development is picking up. RTG's new leadership will be leading the design and execution of the major architecture. The efforts on the engineering side will be spearheaded by David Wang and Mike Rayfield on the execution and business side of things.

AMD has already hinted in its slide deck about the existence of this major architecture. Remember the "Next-Gen" micro-architecture that was listed in their roadmap? Well, its the one and the same. We don't know a lot of details about it at this point apart from the fact that it will be based on the 7nm+ process and will succeed GCN sometime in 2020/2021. If all goes as planned, Navi will be the last iteration of GCN macro architecture that hits the market. Here is the complete list of GCN micro-architectures spanning a course of 8 years (2011-2019):

GCN 1st Generation: Southern Islands

GCN 2nd Generation: Sea Islands

GCN 3rd Generation: Volcanic Islands

GCN 4th Generation: Arctic Islands

GCN 5th Generation: Vega

GCN 6th Generation: Navi

At this time, information is pretty hush hush and we don't even have some tantalizing codenames to offer but one thing is for sure, it looks like AMD is planning to improve performance in leaps and bounds (just like GCN did in 2011) over its predecessor and put AMD firmly back in the top spot. You can think of this like the 'Zen' for the graphics side of things.

AMD's brand new macro architecture will have a similar (or greater) performance differential as the TeraScale to GCN jump

GCN was first introduced in 2011 to succeed the TeraScale series of micro-architectures and was one of the most disruptive innovations of its time putting the company firmly ahead of the competition (at the time) and putting immense pressure on NVIDIA. For the past year however, RTG has struggled to compete for the top spot in the graphics segment and all eyes are waiting for NAVI to arrive (probably in early 2019).

NAVI however, will be the last optimization and iteration of the GCN macro-architecture, the 6th generation to be specific. GCN has had a great run and marked a turning point in AMD's philosophy when it moved from the VLIW (very long instruction word) to an RISC (reduced instruction set based computing) based approach. This meant that GCN required a vastly greater number of transistors on die then TeraScale (the predecessor to GCN) but also resulted in serious performance and GPGPU computational advantages.

It is known that this brand new architecture will result in a leap that is at-least as great as the TeraScale to GCN shift. Since the process will be the 7nm+ optimized node, we can be rest assured that yields will not be a problem (which makes sense considering AMD will want to focus only on the architecture and not bleeding edge node issues at that point). Since the company has other Zen 3 based optimizations planned for this time frame, it is now looking that the company is set to reaching its all-time high of market success on both CPU and GPU sides sometime in 2020/2021.