Micron Spills on GDDR6X
 

It would seem that Micron this morning has accidentally spilled the beans on the future of graphics card memory technologies – and outed one of NVIDIA’s next-generation RTX video cards in the process. In a technical brief that was posted to their website, dubbed “The Demand for Ultra-Bandwidth Solutions”, Micron detailed their portfolio of high-bandwidth memory technologies and the market needs for them. Included in this brief was information on the previously-unannounced GDDR6X memory technology, as well as some information on what seems to be the first card to use it, NVIDIA’s GeForce RTX 3090.

The key innovation for GDDR6X appears to be that Micron is moving from using POD135 coding on the memory bus – a binary (two state) coding format – to four state coding in the form of Pulse-Amplitude Modulation 4 (PAM4). In short, Micron would be doubling the number of signal states in the GDDR6X memory bus, allowing it to transmit twice as much data per clock.

https://www.anandtech.com/show/15978...idias-rtx-3090