3D Chip has posted an article about how a GPU works, in relativly simple terms.  If you want to know why people care more about pipelines than raw speed, and were afraid to ask, this will be worth your while.
“Hello readers and reader, welcome to our new bases series to the subject of graphic cards. Did you not ask you already often how a GPU is constructed and calculates like it of pictures? Did you or want to know already always once how AntiAliasing function or various texture filters? In our bases series to the subject of graphic cards, we will try to explain you all that in simple and intelligible type and manner. In the first part of our series, it concerns the functional method of the GPU.”

Here are some more Graphics Card articles from around the web:

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