NVIDIA NV2A (XGPU / XGPU S / XGPU-B)
About this component
The NV2A is a GeForce3 (NV20/Kelvin family) derivative co-developed by Microsoft and NVIDIA, with an extra vertex unit. As well as drawing graphics it is the northbridge: the CPU, the MCPX and the shared 64 MB of DDR all connect through it, and its internal crossbar lets the CPU and GPU reach memory banks at the same time. Because it holds the memory controller, RAM faults and NV2A faults can look alike on a dead board. It sits under the main heatsink next to the CPU. Part variants: xboxdevwiki: XGPU on 1.0 boards, XGPU S on 1.1–1.4, XGPU-B on 1.6. Differences between revisions are largely undocumented and pin compatibility is unknown.
233MHz GPU derived from the GeForce 3/4 architecture, also handles the northbridge.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.