Compare any two graphics cards:
GeForce GTX 260 vs GeForce GTX 460 SE
IntroThe GeForce GTX 260 comes with a GPU core speed of 576 MHz, and the 896 MB of GDDR3 RAM is set to run at 999 MHz through a 448-bit bus. It also features 192 Stream Processors, 64 Texture Address Units, and 28 Raster Operation Units.
Compare all that to the GeForce GTX 460 SE, which features GPU clock speed of 650 MHz, and 1024 MB of GDDR5 memory set to run at 850 MHz through a 256-bit bus. It also is comprised of 288 Stream Processors, 48 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the GeForce GTX 260 should perform a little bit faster than the GeForce GTX 460 SE in general. (explain)
Texel RateThe GeForce GTX 260 should be a bit (approximately 18%) more effective at AF than the GeForce GTX 460 SE. (explain)
Pixel RateThe GeForce GTX 460 SE will be much (approximately 29%) more effective at AA than the GeForce GTX 260, and will be capable of handling higher resolutions without losing too much performance. (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.
Memory Bandwidth: Memory bandwidth is the max amount of data (in units of megabytes per second) that can be moved over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This 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 in a second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write 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 core clock speed. 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 many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.