GeForce 7800 GS AGP
| NVIDIA G70 GPU Properties for 7800 GS AGP | ||
|---|---|---|
| GPU | NVIDIA G70 | |
| Process and Fabricator | 110nm @ TSMC | |
| Die Size | 18.65mm x 17.9mm (334mm²) | |
| Transistor Count | 302 million | |
| DirectX Shader Model | Shader Model 3.0 | |
| Basic Configuration (VP/FP/ROP) | 8/24/16 | |
| Set Configuration (VP/FP/ROP) | 6/16/8 | |
| Vertex Shader Info | VS3.0 5D FP32, co-issue MADD, branch, tex |
|
| Fragment Processor Info | PS3.0 4D FP32, dual and co-issue MADD/MADD, branch, tex |
|
| ROP Info | 4x FX8/FX16 MSAA (2 subsamples/cycle) 2x Z-only rate, 2x colour-only rate FP/FX blender (inc. FP16) |
|
| Texture processing | 24 FP32 address units, 24 samplers Bi/Tri/Aniso (128-tap), FP16 filtering |
|
| Memory Interface | 256-bit, 4 memory channels GDDR->GDDR3 |
|
| GPU Interface | PCI Express 16X | |
| Display output | 2x dual-link DVI TMDS transmitters, NVIDIA PureVidio | |
The G70 is paired with their BR02 PEG-to-AGP IC at clocks of 375/600, giving the following theoretical rates versus GeForce 6800 Ultra.
Theoretical Rates
| Theoretical Rates for GeForce 7800 GS AGP and GeForce 6800 Ultra AGP | ||
|---|---|---|
| NVIDIA GeForce 7800 GS | NVIDIA GeForce 6800 Ultra | |
| Core Clock | 375MHz | 400MHz |
| Memory Clock | 600MHz | 550MHz |
| Pixel fillrate | 3.00G pixels/sec | 6.40G pixels/sec |
| Texture sampling rate | 12.0G samples/sec | 12.8G samples/sec |
| Z-only fillrate | 6.00G samples/sec | 12.8G samples/sec |
| Vertex transform rate | 0.56G tris/sec | 0.60G tris/sec |
| VP MADD issue rate | 2.25G instr/sec | 2.40G instr/sec |
| FP MADD issue rate | 12.0G instr/sec | 6.40G instr/sec |
| Memory bandwidth | 38.40 GB/sec | 35.20 GB/sec |
You can see that 7800 GS bests 6800 Ultra in one crucial area, due to using G70 rather than NV40. While it's deficient elsewhere, the double MADD issue per-cycle per-unit in G70's fragment shader core helps 7800 GS to a pixel shading advantage over the still-impressive GeForce 6800 Ultra.
On top of that GeForce 7800 GS AGP gets G70's better texture filtering performance and better AA image quality (gamma corrected, transparency), compared to what's available on GeForce 6-series hardware. Being AGP there's no support for SLI, that technology requiring the user to make the leap to PCI Express for their graphics bus.
So it's a new SKU designed to motor through the latest shader-heavy games titles faster than the previous generation of high-end NVIDIA graphics products on AGP, whilst looking better to boot. Let's look at the retail examples we had for testing.
