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 made up of 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 6950, which features core clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1024 MB of GDDR5 RAM. It features 1408 SPUs as well as 88 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6950 should in theory perform a small bit faster than the Radeon HD 6870 overall. (explain)
Texel RateThe Radeon HD 6950 will be quite a bit (about 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 full screen anti-aliasing 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: Memory bandwidth is the largest amount of information (in units of MB per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.