Compare any two graphics cards:
Radeon HD 6770 vs Radeon HD 6870
IntroThe Radeon HD 6770 features a clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also makes use of a 128-bit bus, and uses a 40 nm design. It is made up of 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare those specifications to the Radeon HD 6870, which has clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 memory. It features 1120 SPUs along with 56 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6870 should be 100% faster than the Radeon HD 6770 overall, due to its higher data rate. (explain)
Texel RateThe Radeon HD 6870 should be a lot (about 40%) faster with regards to AF than the Radeon HD 6770. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6870 is a better choice, by a large margin. (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 (measured in megabytes per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster 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 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.