Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6870
IntroThe Radeon HD 6850 comes with a GPU clock speed of 775 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 256-bit bus. It also features 960 Stream Processors, 48 TAUs, and 32 ROPs.
Compare those specifications to the Radeon HD 6870, which features core clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 RAM. It features 1120 SPUs along with 56 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870, in theory, should be a little bit faster than the Radeon HD 6850 overall. (explain)
Texel RateThe Radeon HD 6870 will be much (about 35%) more effective at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6870 is the winner, but it probably won't make a huge difference. (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 information (measured in MB per second) that can be moved past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, 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 texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.