The memory bandwidth of the MX200 is half that of the original MX. This causes a 50% performance disadvantage compared to the original MX. The MX400 is built to the same spec as the original MX, with twice the ememory bandwidth of the MX200. The original GeForce card performs about the same as the original MX/MX400, but consumes more electrical current as it's built on an older die process.
What's the frequency, Kenneth?