Compare any two graphics cards:
Radeon HD 5970 vs Radeon HD 6990
IntroThe Radeon HD 5970 features a clock speed of 725 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 256-bit bus, and makes use of a 40 nm design. It is made up of 1600 SPUs, 160 Texture Address Units, and 64 Raster Operation Units.
Compare all of that to the Radeon HD 6990, which has core clock speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 memory. It features 1536 SPUs as well as 96 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6990 should perform much faster than the Radeon HD 5970 overall. (explain)
Texel RateThe Radeon HD 5970 will be a lot (about 46%) more effective at AF than the Radeon HD 6990. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 5970 is superior to the Radeon HD 6990, 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: Memory bandwidth is the largest amount of data (measured in megabytes per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed 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. Pixel rate is calculated by multiplying the number of Render Output Units 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 output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.