The original BioShock engine, a modified Unreal Engine 2.x, was inadequate to support the game mechanics of the new game, thus the development team chose to work with Unreal Engine 3, modifying it with their own lighting engine and means to simulate the movement and buoyancy of the buildings in Columbia. Because of this, all of the assets for BioShock Infinite had to be made from scratch.
The graphics (Ultra mode) look good, not great. But it's in line with the feel of the game bringing it a very pleasant experience.
As our results will show that you do not need heaps of GPU horsepower at all, the game does look good at Very High image and Ultra mode quality settings.
The world you play in is weird yet immersive and you will have plenty of things to do and places to explore up-there in the clouds. But let's have a look at PC graphics card performance.