Compare any two graphics cards:
GeForce GTX 460 2GB vs Radeon HD 5970
IntroThe GeForce GTX 460 2GB has core speeds of 675 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR5 memory. It features 336 SPUs as well as 56 Texture Address Units and 32 Rasterization Operator Units.
Compare those specs to the Radeon HD 5970, which comes with GPU clock speed of 725 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 256-bit bus. It also is comprised of 1600 SPUs, 160 Texture Address Units, and 64 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5970 should perform much faster than the GeForce GTX 460 2GB in general. (explain)
Texel RateThe Radeon HD 5970 should be quite a bit (more or less 514%) better at texture filtering than the GeForce GTX 460 2GB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 5970 is the winner, by a large margin. (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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
Memory Bandwidth: Bandwidth is the largest amount of information (in units of MB per second) that can be moved past the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount 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 Raster Operations Pipelines 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 rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.