Unexpected performance from RTX 3070Ti, possibly algo limiter?

I have GTX 1080 and RTX 3070Ti and for reason they show about the same performance on my model, about 60 seconds per epoch of 3k samples.

The model is 27 layers (as per summary), mostly conv1d, has about 270k parameters and input sample is about 450 values.

I wonder why is this so? GTX is way older chip and RTX is supposed to have faster tensor cores, 1080 has 2560 cores vs 6144 cores and faster memory on 3070Ti. It’s supposed to be at least 2 times faster before cores efficiency.

Is this some kind of hardware limiter like the one against mining?

I am using TF 2.5 and latest cudnn/cuda 11/studio drivers.

Also I wonder if 3080Ti/3090 would show similar performance since they are not A models.