I think its a silly comparison tbh, because assuming a 3080Ti is coming anytime soon (it could well be a year or more away) the performance measure for it would be graphics and for GA100 it would be compute, deep learning and analytics.
Going by the rumours the 3080 seems the most interesting because people say/assume it has a 102 die.
I would've thought NV would want to release the 3080 TI this year, to make sure they maintain a significant performance advantage over AMD's RDNA 2 GPUs. RDNA 2 GPUs will probably be a lot more competitive with the RTX 3080 and 3070, than the 3080 TI. We also know NV can produce more powerful GPUs than the 3080 TI already, so there should be nothing stopping them from releasing the TI this year.
Also, the GA100 is obviously a very capable GPU for graphics + rendering (as well as other areas compute, deep learning) so not sure why you think it's silly to compare it to the 3080 TI. It represents the best that Nvidia can produce with the current technology (it almost certainly has the most transistors of it's generation, like previous Tesla GPUs). We can see this from the performance stats:
Pixel Rate: 225.6 GPixel/s Texture Rate: 609.1 GTexel/s 19.49 TFLOPS
We can't possibly work out the performance of the 3080 or 3080 TI without looking the specs for the Tesla A100.
No idea what the die the 3080 and 3080 TI will use. Could it end up being the GA102 for both (this is what Techpowerup estimate), or is the 3080 TI definately gonna use a different die?