In a recent technology brief Micron has confirmed that it has been developing GDDR6X memory for NVIDIA's next-generation Ampere graphics card lineup. Micron has been a memory module supplier for the Geforce graphics cards, and this new partnership with Nvidia takes things to a whole new level, by bringing GDDR6X memory type support. Under a comparison on ultra bandwidth solutions, segregated into the GDDR6X column, Micron lists a next-gen NVIDIA card under the "RTX 3090" product name. According to the spec sheet, this card features a total memory capacity of 12 GB GDDR6X, achieved through 12 memory chips with a 384-bit wide memory bus. As we saw today, only 11 of these seem to be populated on the RTX 3090, which, when paired with specifications for the GDDR6X memory chips being capable of 19-21 Gbps speeds, brings total memory subsystem bandwidth towards the 912 - 1008 GB/s range (using 12 chips; 11 chips results in 836 GB/s minimum). It's possible the RTX 3090 product name isn't an official NVIDIA product, but rather a Micron-guessed possibility, so don't look at it as factual representation of an upcoming graphics card. One other interesting aspect from the tech brief is that Micron expects their GDDR6X technology to enable 16 Gb (or 2 GB) density chips with 24 Gbps bandwidth, as early as 2021. You can read over the tech brief - which mentions NVIDIA by name as a development partner for GDDR6X - by following the source link and clicking on the "The Demand for Ultra-Bandwidth Solutions" document.