Compare any two graphics cards:
GeForce GTX 560 Ti vs Radeon HD 3870 X2 1GB
IntroThe GeForce GTX 560 Ti features core speeds of 822 MHz on the GPU, and 1002 MHz on the 1024 MB of GDDR5 RAM. It features 384 SPUs as well as 64 Texture Address Units and 32 ROPs.
Compare those specs to the Radeon HD 3870 X2 1GB, which comes with a GPU core clock speed of 825 MHz, and 1024 MB of GDDR4 RAM set to run at 1126 MHz through a 256-bit bus. It also is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Theoretically speaking, the Radeon HD 3870 X2 1GB should perform a little bit faster than the GeForce GTX 560 Ti overall. (explain)
Texel RateThe GeForce GTX 560 Ti should be quite a bit (approximately 99%) faster with regards to AF than the Radeon HD 3870 X2 1GB. (explain)
Pixel RateThe Radeon HD 3870 X2 1GB will be a bit (more or less 0%) better at anti-aliasing than the GeForce GTX 560 Ti, and also should be able to handle higher screen resolutions better. (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.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Bandwidth is the largest amount of information (in units of megabytes per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better 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 number of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.