Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 7870
IntroThe Radeon HD 5970 makes use of a 40 nm design. AMD has clocked the core speed at 725 MHz. The GDDR5 RAM runs at a frequency of 1000 MHz on this card. It features 1600 SPUs along with 160 Texture Address Units and 64 ROPs.
Compare all that to the Radeon HD 7870, which features a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is made up of 1280 SPUs, 80 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 5970 should be quite a bit faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 5970 should be much (about 190%) better at AF than the Radeon HD 7870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 5970 is superior to the Radeon HD 7870, and very much so. (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 MB per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 again. If 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 texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better 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 most pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.