Graphics processing unit
While the first Xbox's graphics processing unit was produced by NVIDIA, the Xbox 360 uses a chip designed by ATI called Xenos. The chip was developed under the names "C1" and "R500".[48] Xenos contains 48 unified shader units, which are capable of both vertex and pixel shading operations. This is in contrast to older graphics processor designs which utilize separate specialized units for these tasks. The GPU package contains two separate silicon dies, each on a 90 nm chip with a clock speed of 500 MHz; the GPU proper, manufactured by TSMC and a 10 MB eDRAM daughter-die, manufactured by NEC. Thanks to the daughter die, the Xenos can do 4x FSAA, z-buffering, and alpha blending with no appreciable performance penalty on the GPU.[49] The GPU also houses additional capabilities typically separated into a motherboard chipset in PC systems - effectively replacing the northbridge chip. An aluminium heat sink is also implemented to cool the GPU, it is wider and shorter than the CPU heat sink.