Compare any two graphics cards:
GeForce GTX 460 2GB vs Radeon HD 5970
IntroThe GeForce GTX 460 2GB uses a 40 nm design. nVidia has set the core frequency at 675 MHz. The GDDR5 RAM works at a frequency of 900 MHz on this specific card. It features 336 SPUs along with 56 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 5970, which comes with clock speeds of 725 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 RAM. It features 1600 SPUs along with 160 Texture Address Units and 64 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5970 will be 122% faster than the GeForce GTX 460 2GB in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 5970 is quite a bit (more or less 514%) better at AF than the GeForce GTX 460 2GB. (explain)
Pixel RateThe Radeon HD 5970 is a lot (approximately 330%) faster with regards to full screen anti-aliasing than the GeForce GTX 460 2GB, and also able to handle higher 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.
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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.