Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6850
IntroThe Radeon HD 6770 uses a 40 nm design. AMD has set the core speed at 900 MHz. The GDDR5 RAM works at a speed of 1050 MHz on this card. It features 800 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Compare that to the Radeon HD 6850, which features a clock speed of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 256-bit memory bus, and makes use of a 40 nm design. It features 960 SPUs, 48 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6850 should in theory perform much faster than the Radeon HD 6770 in general. (explain)
Texel RateThe Radeon HD 6850 is a bit (approximately 3%) faster with regards to AF than the Radeon HD 6770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6850 is the winner, by a large margin. (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 maximum amount of data (measured in megabytes per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, 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, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount 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 higher this number, the better the video card will be at handling 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 could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs 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 fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.