Rhea
 Original Rhea (X810480) | |
 Revised Rhea (X816970) | |
 Revised Rhea (X816971) | |
| Part Number | X810480 X816970 X816971 |
|---|---|
| Introduced | Mid 2007 |
| Designed By | ATi Microsoft NEC (eDRAM) |
| Codename | C2 |
| Type | GPU |
| Used In | Zephyr_C Falcon |
| Clock Speed | 500MHz |
| Memory | 10MB eDRAM |
| Process | 90nm (Both dies) |
| Package | Flip-chip BGA1017 |
| Predecessor | Y2 |
| Successor | Zeus |
Rhea, also known as Y2.5, is a 90nm GPU and is used on the Zephyr_C and Falcon motherboards. It is the successor to Y2. No significant changes were made to the GPU. The eDRAM was changed from Edifis to Styx-90.
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
- B14L stepping
- 90nm process
eDRAM (Styx-90)
- 10MB 256GB/s eDRAM
- Contains logic for:
- 4-sample anti-aliasing
- Alpha compositing
- Color
- Z/stencil buffering
- FS21 stepping
- 90nm process
Details
All variants of Rhea use the Styx eDRAM.
X810480
The initial version of Rhea. 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. Production of this chip paused sometime between weeks 12 through 20 of 2008, and the X816970 and X816971 chips were produced instead to test fixed chips with different underfill materials. In Late-2009, X810480 chips with higher Tg underfill began being produced. These revised chips are known to be reliable.
- Part Number: X810480
X816970
A revised version of Rhea with higher Tg underfill material that appears dark. Some versions are marked with "Htg85". These chips are known to be reliable.
- Part Number: X816970
X816971
A second revised version of Rhea with higher Tg underfill material that appears milky white. Some versions are marked with "Htg130". These chips are known to be reliable.
- Part Number: X816971