Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 512MB features a GPU core clock speed of 600 MHz, and the 512 MB of GDDR3 memory runs at 900 MHz through a 256-bit bus. It also is made up of 112 Stream Processors, 56 TAUs, and 16 ROPs.
Compare those specifications to the GeForce 9800 GT 1GB, which makes use of a 65/55 nm design. nVidia has clocked the core frequency at 600 MHz. The GDDR3 memory works at a frequency of 900 MHz on this card. 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 memory bandwidth, so in theory they should perform the same. (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 theoretically they should perform equally good at at full screen anti-aliasing, and be able to handle 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 max amount of information (measured in megabytes per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's 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 can be applied in one second. This number is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.