Compare any two graphics cards:
Radeon HD 3870 X2 1GB vs Radeon HD 5970
IntroThe Radeon HD 3870 X2 1GB has a clock frequency of 825 MHz and a GDDR4 memory speed of 1126 MHz. It also uses a 256-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.
Compare all of that to the Radeon HD 5970, which comes with core speeds of 725 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 1600 SPUs along with 160 TAUs and 64 ROPs.
Power Usage and Theoretical Benchmarks
Theoretically speaking, the Radeon HD 5970 should be 78% faster than the Radeon HD 3870 X2 1GB overall, because of its greater data rate. (explain)
Texel RateThe Radeon HD 5970 should be much (approximately 779%) more effective at anisotropic filtering than the Radeon HD 3870 X2 1GB. (explain)
Pixel RateThe Radeon HD 5970 will be a lot (more or less 252%) faster with regards to anti-aliasing than the Radeon HD 3870 X2 1GB, and should be able to handle higher resolutions without slowing down too much. (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 maximum amount of data (in units of megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 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 AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the local memory in one 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 rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.