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 RAM runs at 1050 MHz through a 128-bit bus. It also is made up of 800 Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.
Compare all of that 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 SPUs, 56 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6870 should perform much faster than the Radeon HD 6770 overall. (explain)
Texel RateThe Radeon HD 6870 is a lot (more or less 40%) better at texture filtering than the Radeon HD 6770. (explain)
Pixel RateThe Radeon HD 6870 should be quite a bit (about 100%) more effective at full screen anti-aliasing than the Radeon HD 6770, and able to handle higher screen resolutions better. (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 information (measured in megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 can be processed per second. This number is calculated by multiplying the total number of texture units by the core clock 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 in a 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. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.