Most people don't have a very good understanding of voxel games and think they should run at the same frame rates as a first person shooter and that couldn't be further from the reality.
It is also worth noting that the game is still experimental Alpha, it's not even stable Alpha yet and most of the performance enhancing features haven't even been added yet so right now there is massive overdraw in towns and cities which is wrecking your FPS.
This still doesn't mean you can play the game with a potato and expect 60+ frames per second, that is completely unrealistic.
It is also worth noting that the game is still experimental Alpha, it's not even stable Alpha yet and most of the performance enhancing features haven't even been added yet so right now there is massive overdraw in towns and cities which is wrecking your FPS.
This still doesn't mean you can play the game with a potato and expect 60+ frames per second, that is completely unrealistic.