Compare any two graphics cards:
Radeon HD 3470 256MB vs Radeon HD 3470 512MB
IntroThe Radeon HD 3470 256MB makes use of a 55 nm design. AMD has set the core frequency at 800 MHz. The DDR2 memory runs at a speed of 950 MHz on this particular card. It features 40(8x5) SPUs along with 4 Texture Address Units and 4 Rasterization Operator Units.
Compare those specifications to the Radeon HD 3470 512MB, which makes use of a 55 nm design. AMD has set the core frequency at 800 MHz. The GDDR3 memory is set to run at a frequency of 950 MHz on this specific card. It features 40(8x5) SPUs along with 4 TAUs and 4 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Both cards have exactly the same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so theoretically they should be equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should be equally good at at AA, and be capable of handling the same resolutions. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
Memory Bandwidth: Memory bandwidth is the max amount of information (in units of MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.