Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 6950
IntroThe Radeon HD 6870 uses a 40 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 RAM runs at a speed of 1050 MHz on this specific model. It features 1120 SPUs as well as 56 Texture Address Units and 32 Rasterization Operator Units.
Compare those specifications to the Radeon HD 6950, which comes with a GPU core clock speed of 800 MHz, and 1024 MB of GDDR5 RAM set to run at 1250 MHz through a 256-bit bus. It also features 1408 Stream Processors, 88 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 is 19% faster than the Radeon HD 6870 overall, because of its higher data rate. (explain)
Texel RateThe Radeon HD 6950 will be quite a bit (more or less 40%) faster with regards to AF than the Radeon HD 6870. (explain)
Pixel RateThe Radeon HD 6870 should be a bit (more or less 13%) more effective at AA than the Radeon HD 6950, and also should 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.
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 max amount of data (counted in MB per second) that can be moved over the external memory interface in a second. It's calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.