Legit Reviews posted a review on integrated vs Budget ATI and Nvidia Video Cards

So what we did learn here? That integrated video is slower compared to even the least expensive cards on the market including an add-in board with the same name. The X300 was much faster while the 6200TC was easily capable of doubling the performance of the integrated video in all but one situation. It's really important to point out that the integrated video and the ATI card in this test are using the same GPU, but they are clocked at different speeds and have much different ways of accessing the memory, which is why there is such a difference in our tests. This should illustrate just how much more efficient an add-in board is.

Integrated vs Budget ATI and Nvidia Video Cards