Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 6950
IntroThe Radeon HD 6870 features a GPU core speed of 900 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1050 MHz through a 256-bit bus. It also is comprised of 1120 Stream Processors, 56 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 6950, which comes with GPU core speed of 800 MHz, and 1024 MB of GDDR5 RAM running at 1250 MHz through a 256-bit bus. It also is made up of 1408 Stream Processors, 88 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6950 will be 19% quicker than the Radeon HD 6870 in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 6950 should be much (more or less 40%) faster with regards to anisotropic filtering than the Radeon HD 6870. (explain)
Pixel RateThe Radeon HD 6870 is a bit (more or less 13%) faster with regards to anti-aliasing than the Radeon HD 6950, and should be able to handle higher resolutions more effectively. (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: Memory bandwidth is the max amount of data (measured in MB per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory clock speed. If the card has DDR type memory, the result should 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 anti-aliasing, 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 amount of texture units by the core speed of the chip. The better this number, the better the video 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 maximum amount of pixels that the graphics chip could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.