First reviews are out, and the RTX 3090 Ti appears to be around 7% faster than the RTX 3090 on average. Initial availability is expected to be very limited, but, on the bright side, the new model is considerably quieter due to the bulky cooling solution and the GDDR6X is not overheating anymore.
https://www.notebookcheck.net/Nvidia-launches-the-RTX-3090-Ti-Founders-Edition-for-US-1-999-with-minimum-performance-gains-and-very-low-initial-stock.610486.0.html