Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 512MB
IntroThe GeForce 8800 GT 512MB has core speeds of 600 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 112 SPUs as well as 56 TAUs and 16 ROPs.
Compare all that to the GeForce 9800 GT 512MB, which comes with core speeds of 600 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 RAM. It features 112 SPUs as well as 56 TAUs and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Both cards have exactly the 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 perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have exactly the same pixel fill rate, so in theory they should be equally good at at AA, 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: Bandwidth is the maximum amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 again. If 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, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units of the card 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 processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core 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 many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.