Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 512MB
IntroThe GeForce 8800 GT 512MB uses a 65 nm design. nVidia has clocked the core frequency at 600 MHz. The GDDR3 RAM works at a frequency of 900 MHz on this model. It features 112 SPUs along with 56 Texture Address Units and 16 Rasterization Operator Units.
Compare those specifications to the GeForce 9800 GT 512MB, which features a clock speed of 600 MHz and a GDDR3 memory speed of 900 MHz. It also uses a 256-bit memory bus, and uses a 65/55 nm design. It is comprised of 112 SPUs, 56 TAUs, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have exactly the same bandwidth, so theoretically they should perform exactly the same. (explain)
Texel RateBoth cards have the exact same texel rate, so theoretically they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have exactly the same pixel rate, so in theory they should be equally good at at FSAA, and be able to handle 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: Bandwidth is the maximum amount of data (in units of megabytes per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster 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 processed per second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, 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 maximum amount of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.