d43

does anyone know the story behind the Hynix d43 chips, I'm seeing them used for everything from 3-3-3-8 400, Kingston value DDR 400 to 2-3-3-5 400, Legend overthruster DDR 400 to 3-4-4-8 500 Corsair TWINX DDR-500 modules. why would any manufacturer use fast chips and set the spd to lower...