It's barely faster than an overclocked 3080 (stock firmware).
Look for example at these benchmarks, EVGA 3080 FTW3 Ultra vs 3080 Ti FTW3 Ultra:
The EVGA RTX 3080 FTW3 Ultra is extremely impressive. It is the fastest RTX 3080 we've reviewed so far, thanks to a massively increased power limit. The new iCX cooler works well, reaching amazing noise levels that are better than most other RTX 3080 cards, and fan-stop is included, too.
www.techpowerup.com
EVGA's GeForce RTX 3080 Ti FTW3 Ultra comes with a large factory overclock, which results in out-of-the-box performance higher than even the RTX 3090. EVGA is also including nine additional temperature sensors and a large power limit adjustment range of up to 450 W.
www.techpowerup.com
The FPS are almost identical and the non-Ti was tested with an Intel Core i9-9900K, which is slower than AMD Ryzen 7 5800X used to test the Ti.