Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6870
IntroThe Radeon HD 6770 has a GPU core speed of 900 MHz, and the 512 MB of GDDR5 memory is set to run at 1050 MHz through a 128-bit bus. It also features 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare those specs to the Radeon HD 6870, which comes with GPU core speed of 900 MHz, and 1024 MB of GDDR5 RAM set to run at 1050 MHz through a 256-bit bus. It also features 1120 Stream Processors, 56 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870 should theoretically be quite a bit faster than the Radeon HD 6770 in general. (explain)
Texel RateThe Radeon HD 6870 will be a lot (about 40%) more effective at texture filtering than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 6870 should be a lot (more or less 100%) better at anti-aliasing than the Radeon HD 6770, and also will 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 largest amount of information (measured in megabytes per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.