Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce 9800 GT 1GB
IntroThe GeForce 8800 GT 512MB comes with core clock 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 Texture Address Units and 16 ROPs.
Compare all that to the GeForce 9800 GT 1GB, which features 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.
(No game benchmarks for this combination yet.)
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 exactly the same. (explain)
Texel RateBoth cards have the exact same texel fill rate, so in theory they should perform equally good at at anisotropic filtering. (explain)
Pixel RateBoth cards have the exact same pixel rate, so in theory they should be equally good at at AA, 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 largest amount of information (measured in MB per second) that can be transferred past the external memory interface within a second. It's worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total amount of texture units 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 applied in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.