We now know the final specs for the reference RTX 3080 Ti cards, including the base and boost clocks, VRAM specs and TGP. Performance should be very close to an RTX 3090, but the first Ashes of the Singularity tests do not seem to support this.
https://www.notebookcheck.net/Full-RTX-3080-Ti-reference-specs-revealed-by-GPU-Z-validation-plus-some-Ashes-of-the-Singularity-scores.541457.0.html