Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 6990
IntroThe Radeon HD 5970 features a GPU core clock speed of 725 MHz, and the 1024 MB of GDDR5 RAM runs at 1000 MHz through a 256-bit bus. It also is comprised of 1600 Stream Processors, 160 Texture Address Units, and 64 ROPs.
Compare those specifications to the Radeon HD 6990, which comes with a core clock frequency of 830 MHz and a GDDR5 memory frequency of 1250 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is comprised of 1536 SPUs, 96 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6990 should in theory perform much faster than the Radeon HD 5970 overall. (explain)
Texel RateThe Radeon HD 5970 should be much (approximately 46%) better at anisotropic filtering than the Radeon HD 6990. (explain)
Pixel RateThe Radeon HD 5970 is quite a bit (approximately 75%) faster with regards to AA than the Radeon HD 6990, 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: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the interface width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number 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 in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called 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 - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.