GeForce 7800 GTX architecture can be seen in Figure 2.

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Figure 2: GeForce 7800 GTX overall architecture.

The big blocks in the center are the pixel shader pipelines. As you can see, there are six blocks with four pipelines each, for a total of 24 pixel shader pipelines. Below them you can see a mention to a texture L2 cache that we will talk about in a sec. At the top you will find eight blocks, which are the eight vertex shaders pipelines of this chip.

In Figure 3, you can see the block diagram of one vertex shader pipeline and in Figure 4 you can see the block diagram of one pixel shader pipeline. As you can see, both vertex shader and pixel shader pipelines have access to a L2 texture cache, which increases the chip performance, and pixel shader pipeline has access to a L1 texture cache.

 
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Figure 3: GeForce 7800 GTX vertex shader pipeline.

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Figure 4: GeForce 7800 GTX pixel shader pipeline.

On GeForce 7800 series more computational power was put inside the pixel shaders. On GeForce 6800 series, the pixel shader pipeline consisted of two shader units with a texture unit between them. Each shader unit had a 4 operations per pixel power, for a total of eight operations per pixel. On GeForce 7800 GTX architecture, the texture unit was moved and put on the side of the first shader unit (and not between the units) and the performance of each shader unit was increased to 10 operations per pixel, for a total of 20 operations per pixel, a 150% performance increase over GeForce 6800 architecture. Impressive.