Compare any two graphics cards:
Radeon HD 6990 vs Radeon HD 7970
IntroThe Radeon HD 6990 has core speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs as well as 96 Texture Address Units and 32 ROPs.
Compare those specifications to the Radeon HD 7970, which features core speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6990 should in theory be much faster than the Radeon HD 7970 overall. (explain)
Texel RateThe Radeon HD 6990 should be quite a bit (approximately 35%) better at AF than the Radeon HD 7970. (explain)
Pixel RateThe Radeon HD 6990 will be quite a bit (more or less 79%) faster with regards to FSAA than the Radeon HD 7970, and also 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: Bandwidth is the maximum amount of information (measured in megabytes per second) that can be moved over the external memory interface within a second. The number is worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.