Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6870
IntroThe Radeon HD 6770 features a core clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It is made up of 800 SPUs, 40 TAUs, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 6870, which has a core clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also features a 256-bit bus, and makes use of a 40 nm design. It features 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 6870 should in theory be quite a bit superior to the Radeon HD 6770 in general. (explain)
Texel RateThe Radeon HD 6870 will be much (approximately 40%) more effective at anisotropic filtering than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 6870 is much (more or less 100%) more effective at full screen anti-aliasing than the Radeon HD 6770, and also will be capable of handling higher resolutions while still performing well. (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 data (counted in MB per second) that can be transferred past the external memory interface in one second. It is worked out by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it must 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 AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the 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 maximum number of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.