In brief: Micron has just updated its website with new information on the GDDR6X modules it's producing, which are expected to appear in the upcoming Nvidia RTX 4000 series. In addition to 16Gb (2GB) modules featuring 21 Gbps speeds, there's also a listing for 24 Gbps GDDR6X that could be used in the recently rumored flagship, possibly a new Titan, that's said to pack 48GB of VRAM, 18,176 CUDA cores, and an 800 TDP.
VideoCardz noticed Micron's update. It confirms the 21 Gbps GDDR6X modules set to appear in the high-end Ada Lovelace RTX 4000 series, most likely the RTX 4070, 4080, and 4090 cards and their Ti variants.
There's also mention of 24 Gbps GDDR6X. This isn't the first time we've heard of such video memory packing these speeds; it was included in specs last month for an alleged Ada Lovelace flagship. That particular card is supposedly based on a new PG139-SKU0 board design rather than the PG137 expected to be utilized by the RTX 4090 and could be the first to feature a triple-fan reference cooler from Nvidia.
With 48GB of 24 Gbps GDDR6X and a 384-bit bus interface, enabling a maximum bandwidth of 1.15 TB/s---an increase of about 14% over the RTX 3090 Ti---it's theorized that this card will be the first Titan-branded Nvidia product we've seen since 2018, or it could be another workstation card. Either way, expect it to be aimed at scientists, researchers, and content creators rather than gamers.
It is noted, though, that just because the 24 Gbps GDDR6X is being produced, there's no guarantee it will end up as part of Lovelace.
The good news is that even the mid-range RTX 4000 series is said to pack a punch that will put the current-gen equivalents to shame. The RTX 4070 and its Ti variant are both expected to feature 21 Gbps speeds, and even the former is said to feature 7,680 CUDA cores or 60 Streaming Multiprocessors, 30 billion transistors, and 12GB of GDDR6X on a 192-bit bus, giving it a maximum 504 GB/s bandwidth. With a claimed Time Spy Extreme score of over 11,000, the RTX 4070 could come close to matching the RTX 3090 Ti flagship.