Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6850
IntroThe Radeon HD 6770 uses a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 RAM runs at a frequency of 1050 MHz on this particular model. It features 800 SPUs as well as 40 TAUs and 16 ROPs.
Compare those specs to the Radeon HD 6850, which comes with a core clock speed of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It features 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6850 should perform a lot faster than the Radeon HD 6770 in general. (explain)
Texel RateThe Radeon HD 6850 will be a small bit (about 3%) faster with regards to anisotropic filtering than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 6850 will be quite a bit (more or less 72%) faster with regards to full screen anti-aliasing than the Radeon HD 6770, and should be able to handle higher resolutions without losing too much performance. (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 maximum amount of data (measured in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 per second. This number 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 graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the card's clock speed. 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.