Specs., fillrate and shading
Both cards differ in rendering and bandwidth. Let's take a closer look. I've also added in a GeForce 6800 GT 256MB PCI-Express card. It will show where both midrange cards stand in relation to a high-end performer.| Card | GALAXY GeForce 6600 | ASUS EN5900 PCIe | ASUS AX600XT/HTVD PCIe |
| Manufacturing process | 110nm | 130nm | 130nm |
| Interface | PCI-Express (X16) | PCI-Express (X16) | PCI-Express (X16) |
| Render setup | 8x1 | 4x1 | 4x1 |
| Onboard memory | 256MB | 128MB | 128MB |
| Core speed | 325MHz | 375MHz | 500MHz |
| Single-texture fillrate | 2600MPixel/s | 1500MPixel/s | 2000MPixel/s |
| Texture units | 1 | 2 | 1 |
| Multi-texture fillrate | 2600MTexels/s | 3000MTexels/s | 2000MTexels/s |
| Memory speed | 550MHz | 700MHz | 740MHz |
| Memory bus width | 128-bit | 256-bit | 128-bit |
| Memory bandwidth | 8.8GB/s | 22.4GB/s | 11.8GB/s |
| Estimated price | £125 | £165 | £130 |
| Other features | Native PCIe, PS+VS 3.0 | Bridged AGP design PS+VS 2.0 | Native PCIe, PS+VS 2.0 |
The GeForce 6600 (codenamed NV43) can be thought of as a stunted NV40. As you may know, NVIDIA is structuring pipelines in a so-called 'quads', with each quad comprising four pixel pipelines. The 6800 GT and Ultra use a full complement of 4 quads, offering 16 rendering pipelines in all. Shading is also much-improved from previous generation's. The NV40 boasts a total 6 vertex shaders and a juicy 256-bit memory bus. The 6600 derivative has exactly half of the NV40's clout: two quads, 3 vertex shaders and a 128-bit interface, but it retains its bigger brothers' advanced Shader Model 3.0 and other nice technological tit bits.
Looking at our review card in particular, GALAXY's move to use 256MB of onboard memory is probably a wise one. 600MHz-rated chips aren't prohibitively expensive and the use of a larger framebuffer should come in handy when we look at either high resolutions and/or AntiAliasing/Anisotropic Filtering. As a preliminary check, I ran 3DMark03's shading and fillrate tests to get a handle on probable game performance. All tests were run at 1024x768.
The 6600 doesn't look so great in a single-texturing scenario. The GPU falls way short of its theoretical 2600MPixels/s fillrate. How about multi-texturing?.
Shading is an area in which the NV43 should be good at. It manages to out-shade a PCX5900 card running with a ~15% core clock speed advantage.
Pixel shading is also impressive, to say the very least. Benchmarks should be interesting.