In the run up to Intel?s PCI Express launch NVIDIA?s "NV45" turned up, boasting PCI Express compatibility. Whilst on first glance this appeared to have been a native PCI Express implementation, closer inspection revealed NVIDIA "HSI" bridge chip integrated onto the graphics core?s package. Here Beyond3D takes a look at NV45, in its GeForce 6800 GT PCI Express guise, and measure its performance against the standard AGP GeForce 6800. "NVIDIA's PCX line of boards, which featured AGP GeForce FX's bridged with the HSI chip, all had very different layouts from their standard AGP counterparts, which was required due to the discrete HSI chip on the board which resulted in the core and memory needed to be shifted around the board. With the high memory speeds and 256-bit bus of GeForce 6800, board space and positioning is at a premium as the trace paths and lengths are fairly critical, hence a discrete HSI solution may have been difficult to implement."
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