Compare any two graphics cards:
Radeon HD 3870 X2 1GB vs Radeon HD 5970
IntroThe Radeon HD 3870 X2 1GB comes with a clock speed of 825 MHz and a GDDR4 memory speed of 1126 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.
Compare those specs 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 memory. It features 1600 SPUs as well as 160 Texture Address Units and 64 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
In theory, the Radeon HD 5970 should be a lot faster than the Radeon HD 3870 X2 1GB overall. (explain)
Texel RateThe Radeon HD 5970 is a lot (more or less 779%) better at texture filtering than the Radeon HD 3870 X2 1GB. (explain)
Pixel RateThe Radeon HD 5970 is much (more or less 252%) faster with regards to AA than the Radeon HD 3870 X2 1GB, and also will be able to handle higher screen 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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be moved across the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.