Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6870
IntroThe Radeon HD 6770 comes with a GPU core speed of 900 MHz, and the 512 MB of GDDR5 RAM is set to run at 1050 MHz through a 128-bit bus. It also is comprised of 800 SPUs, 40 TAUs, and 16 ROPs.
Compare those specifications to the Radeon HD 6870, which features a core clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It features 1120 SPUs, 56 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 6870 should theoretically be much superior to the Radeon HD 6770 overall. (explain)
Texel RateThe Radeon HD 6870 should be much (about 40%) better at texture filtering than the Radeon HD 6770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6870 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: Memory bandwidth is the maximum amount of data (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's calculated by multiplying the interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.