NVIDIA's approach to unified architecture as detailed in the diagram below, was to get rid of the vertex and pixel shader pipelines as we know them, and replace those with completely decoupled "stream processors", as they are being dubbed. In the case of the 8800 GTX, the core clock speed is 575 MHz (500 MHz on the GTS). In a standard GPU this would implicate that the vertex and pixel shading units also run at this speed. In 8800 series architecture however, these units (now bundled together as stream processors) run at a completely seperate clock speed which in the 8800 GTX's instance, is 1350 MHz (1200 MHz on the GTS).



Link: Neoseeker