|Instruction Set||PowerPC RISC|
They are named after the fictional character Henry J. Waternoose III.
- 3 two-way SMD-capable RISC cores clocked at 3.2GHz
- SIMD: Two VMX128 units
- 32KB L1 data cache
- 32KB L1 instruction cache
- 1MB L2 cache at 1.6 GHz with a 256-bit bus
- 21.6GB/s FSB
- 768 bits of IBM eFUSE one-time-program memory
- ROM and 64KB SRAM for storing the 1BL
- Big-endian architecture
- A00 stepping (DD1, DD3)
- B00 stepping (DD2)
- B01 stepping (DD2.1)
- 90nm process
- TDP: 75W/85W
DD1 is the engineering sample of the XCPU with A00 stepping, labelled XCPU-ES. It runs at 2.8GHz as opposed to the final speed of 3.2GHz. Due to mistakes in the POR sequence, these CPUs can only boot with a Titan board functioning as a service processor to bring up the CPU. It still has the original Xbox logo as it was created before the Xbox 360 name was chosen.
- Part Number: X02046 (-001)
DD2 is the initial production version of the XCPU with B00 stepping, running at 3.2GHz. Very early versions with part number X02046-002 used in certain pre-final consoles were still labelled "XCPU-ES" and ran at 2.8GHz.
- Part Number: X02046 (-002 and -003)
DD2.1 is a minor revision of DD2 with B01 stepping, that improves yield and binned chips for 75W and 85W. This allowed most motherboards to have 75W CPUs.
- Part Number: X02046 (-004 and up)
DD3 is a revision of DD2 that fixes minor design issue. With the new part number, the stepping reset to A00. All chips are 75W. It also adds little-endian support which was unused due to all software features requiring full compatibility with the earlier DD2 chip.
- Part Number: X806416