Compare any two graphics cards:
GeForce 8800 GT 1GB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 1GB uses a 65 nm design. nVidia has set the core frequency at 600 MHz. The GDDR3 memory is set to run at a speed of 900 MHz on this model. It features 112 SPUs along with 56 Texture Address Units and 16 ROPs.
Compare all of that to the GeForce 9800 GT 1GB, which comes with GPU core speed of 600 MHz, and 1024 MB of GDDR3 RAM set to run at 900 MHz through a 256-bit bus. It also features 112 SPUs, 56 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have the exact same bandwidth, so theoretically they should have the same performance. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so theoretically they should be equally good at at AF. (explain)
Pixel RateBoth cards have the exact same pixel fill rate, so in theory they should be equally good at at full screen anti-aliasing, and be capable of handling the same screen 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.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.