Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 512MB features a GPU core speed of 600 MHz, and the 512 MB of GDDR3 memory is set to run at 900 MHz through a 256-bit bus. It also features 112 SPUs, 56 TAUs, and 16 Raster Operation Units.
Compare that to the GeForce 9800 GT 1GB, which comes with core speeds of 600 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR3 memory. It features 112 SPUs as well as 56 Texture Address Units and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have exactly the same bandwidth, so in theory they should perform exactly the same. (explain)
Texel RateBoth cards have exactly the same texel fill rate, so in theory they should perform equally good at at AF. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so theoretically they should perform equally good at at full screen anti-aliasing, 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.
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 maximum amount of information (in units of MB per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.