ATI Radeon X800 PRO
| Product | Radeon X800 PRO - ATI R420 | Radeon X800 XT - ATI R420 |
| Process | 130nm @ TSMC low-k | 130nm @ TSMC low-k |
| Transistor Count | 160M | 160M |
| Geometry Pipeline | VS2.0* | VS2.0* |
| Fragment Processor | PS2.0* | PS2.0* |
| Fragment Processor Setup | 2 full (vector/scalar) ALU (not equal), one texture ALU, F-buffer | 2 full (vector/scalar) ALU (not equal), one texture ALU, F-buffer |
| Fragment Processor Precision | FP24 | FP24 |
| Traditional Render Setup | 12 x 1 | 16 x 1 |
| Vertex Shaders | 6 | 6 |
| Basic Texture Filtering | Trilinear | Trilinear |
| Texture Filtering | Bilinear, Trilinear, 16X Anisotropic | Bilinear, Trilinear, 16X Anisotropic |
| Antialiasing | Multi-sampling | Multi-sampling |
| AA Sample Type | Scattered/sparse grid, up to 6X | Scattered/sparse grid, up to 6X |
| Bus Support | AGP8X | AGP8X |
| Memory support | GDDR3** | GDDR3** |
| Basic Core Frequency | 475MHz | 520MHz |
| Basic Memory Frequency | 900MHz | 1120MHz |
| Memory Bus Width | 256-bit, 4 partition memory crossbar | 256-bit, 4 partition memory crossbar |
| Basic Pixel Fillrate | 5700Mpixel/sec | 8320Mpixel/sec |
| Basic Multitexture Fillrate | 5700Mtexel/sec | 8320Mtexel/sec |
| Basic Memory Bandwidth | ~28.80GB/sec | ~35.84GB/sec |
With all the same basic rendering features intact, the differences between the PRO and XT are easy to spot. One quad pixel pipe less than XT and a drop in core and memory frequency are what define the PRO.
Pixel and texel fillrate are some 70% of the XT, while memory frequency is 80% of its bigger brother. A sizeable step in performance and one that should easily mark out a noticable difference between the two.
Let's have a look at the reference board.
