Although it's true that the 8GB and 12GB variants of the GeForce RTX 3060 are based on the same silicon, the changes go beyond memory capacity and the 8GB RTX 3060 is always going to be slower.
Nvidia GeForce RTX 3060 8GB: Why You Should Avoid It
Although it's true that the 8GB and 12GB variants of the GeForce RTX 3060 are based on the same silicon, the changes go beyond memory capacity and the 8GB RTX 3060 is always going to be slower.