Compare any two graphics cards:
GeForce 8800 GT 512MB vs GeForce GTX 780 Ti
IntroThe GeForce 8800 GT 512MB comes with a GPU clock speed of 600 MHz, and the 512 MB of GDDR3 memory is set to run at 900 MHz through a 256-bit bus. It also features 112 SPUs, 56 TAUs, and 16 ROPs.
Compare those specs to the GeForce GTX 780 Ti, which comes with a GPU core clock speed of 875 MHz, and 3072 MB of GDDR5 memory running at 1750 MHz through a 384-bit bus. It also is made up of 2880 Stream Processors, 240 Texture Address Units, and 48 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 780 Ti should in theory perform quite a bit faster than the GeForce 8800 GT 512MB overall. (explain)
Texel RateThe GeForce GTX 780 Ti should be quite a bit (more or less 525%) better at AF than the GeForce 8800 GT 512MB. (explain)
Pixel RateIf using high levels of AA is important to you, then the GeForce GTX 780 Ti is superior to the GeForce 8800 GT 512MB, and very much so. (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 (counted in MB per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, 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 figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the core 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.