Complex sentence: Under normal conditions it beat the "GeForce4 Ti4600" by around 15-20%, the previous speed king, and when anti-aliasing and/or anisotropic filtering were switched on it beat the "Ti4600" by anywhere from 40-100%.
Split into simpler sentences: Under normal conditions it beat the "GeForce4 Ti4600" by around 15-20%, the previous speed king. However, when anti-aliasing and/or anisotropic filtering were switched on it would beat the "Ti4600" by anywhere from 40-100%.