Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7770
IntroThe Radeon HD 6870 has a clock frequency of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 256-bit bus, and uses a 40 nm design. It features 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.
Compare those specifications to the Radeon HD 7770, which comes with a GPU core clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 640 SPUs, 40 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6870 should be much faster than the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 6870 should be much (approximately 26%) more effective at anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateThe Radeon HD 6870 should be a lot (approximately 80%) more effective at anti-aliasing than the Radeon HD 7770, and also should be capable of handling higher screen resolutions more effectively. (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 (counted in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better 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 number of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.