According to a source in the ChipHell forum, NVIDIA is planning to debut its top-of-the-line GeForce RTX 3090 Ti "Ampere" graphics card on March 29, 2022. 

Additionally, the same source indicates that NVIDIA has abandoned plans to release a 16 GB variant of the performance-segment GeForce RTX 3070 Ti, implying that the company is likely wrapping up its RTX 30-series Ampere product-stack updates this Spring-Summer in order to prepare for its next-generation RTX 40-series based on the "Ada Lovelace" graphics architecture, with mid-year announcements and product launches in.

As always, these are unconfirmed rumors, so please do take them as such.

Update: According to the information provided by VideoCardz, the GeForce RTX 3090 Ti will be available for purchase on Tuesday, March 29. That date he card would also be formally launched at the same moment, and the press reviews would be released at the same time. According to the company's website, this planning comes from one of Nvidia's board partners, which manufacture video cards that are based on Nvidia's graphics processing units (GPU). Nvidia GeForce RTX 3090 Ti will be equipped with a GA-102 GPU with 10,752 CUDA cores. In addition, the video card is equipped with 24GB of GDDR6X memory with a transfer rate of 21Gbit/s. The existing RTX 3090 has 10,496 CUDA cores and 24GB GDDR6X memory with a transfer rate of 19.5Gbit/s, whilst the new model has slightly more cores and a little higher transfer rate of 19.5Gbit/s. Aside from that, the RTX 3090 Ti would have faster clock rates and TGPs, and it would come with a new power connection as well.