Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6850
IntroThe Radeon HD 6770 has a clock frequency of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 128-bit bus, and uses a 40 nm design. It is comprised of 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare that to the Radeon HD 6850, which uses a 40 nm design. AMD has clocked the core speed at 775 MHz. The GDDR5 memory is set to run at a speed of 1000 MHz on this model. It features 960 SPUs as well as 48 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
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 overall. (explain)
Texel RateThe Radeon HD 6850 will be a little bit (more or less 3%) more effective at texture filtering than the Radeon HD 6770. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 6850 is the winner, and very much so. (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 max amount of information (measured in MB per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, 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 can be applied in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics 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 most pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.