Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 7770
IntroThe Radeon HD 6850 has a GPU core clock speed of 775 MHz, and the 1024 MB of GDDR5 memory is set to run at 1000 MHz through a 256-bit bus. It also features 960 SPUs, 48 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 7770, which features 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 made up of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6850 should perform much faster than the Radeon HD 7770 overall. (explain)
Texel RateThe Radeon HD 7770 is a small bit (about 8%) more effective at AF than the Radeon HD 6850. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6850 is a better choice, by far. (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 data (measured in megabytes per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 number of texture map elements (texels) that are processed per second. This is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.