Compare any two graphics cards:
GeForce GTX 260 vs GeForce GTX 460 SE
IntroThe GeForce GTX 260 makes use of a 65 nm design. nVidia has clocked the core frequency at 576 MHz. The GDDR3 memory works at a speed of 999 MHz on this card. It features 192 SPUs along with 64 TAUs and 28 ROPs.
Compare all that to the GeForce GTX 460 SE, which features a GPU core clock speed of 650 MHz, and 1024 MB of GDDR5 memory running at 850 MHz through a 256-bit bus. It also features 288 Stream Processors, 48 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 260 is 3% faster than the GeForce GTX 460 SE in general, because of its higher data rate. (explain)
Texel RateThe GeForce GTX 260 will be a small bit (about 18%) more effective at anisotropic filtering than the GeForce GTX 460 SE. (explain)
Pixel RateThe GeForce GTX 460 SE should be a lot (about 29%) better at full screen anti-aliasing than the GeForce GTX 260, and also capable of handling higher screen resolutions more effectively. (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 maximum amount of data (counted in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better this number, 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 most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.