Y1 (GPU)

Y1

Original Y1 (X02056)
Revised Y1 (X817791)
Part Number	X02056 X817791
Introduced	Late 2005
Designed By	ATi Microsoft NEC (eDRAM)
Codename	A32
Type	GPU
Used In	Xenon Zephyr_A
Clock Speed	500MHz
Memory	10MB eDRAM
Process	90nm (Both dies)
Package	Flip-chip BGA1017
Successor	Y2

Y1 is the launch model GPU used in the Xbox 360. It is manufactured on a 90nm process and has the A32 design. The eDRAM is also 90nm.

Specifications

GPU

• 500Mhz clock speed
• 48 floating-point vector processors divided into 3 dynamically scheduled SIMD groups (16 each)
• Unified shader architecture
• 16 texture addressing units
• 16 texture filtering units
• 8 pixel rendering pipelines
• Direct access to CPU L2 cache
• 90nm process

eDRAM

• 10MB 256GB/s eDRAM
• Contains logic for:
  • 4-sample anti-aliasing
  • Alpha compositing
  • Color
  • Z/stencil buffering
• 90nm process

Details

X02056

The initial version of the GPU Y1, used in the launch model consoles. This chip contains a design defect in which low Tg underfill is used to support the bumps. This causes reliability issues and premature failure of the chip. Starting sometime between weeks 12 through 20 of 2008, chips with higher Tg underfill began being produced. These revised chips are known to be reliable.

• Part Number: X02056
• Foundries:
  • Korea Foundry
  • Taiwan Foundry

X817791

In Mid 2008, GPU Y1 received a revision and part number change. "GPU - Y1" markings were added to differentiate from other in-production chips. It used a higher Tg underfill material and as a result, is known to be reliable. It is not known if other differences were made in this variant.

• Part Number: X817791
• Foundries:
  • Korea Foundry