Compare any two graphics cards:
Radeon HD 7770 vs Radeon HD 7850
IntroThe Radeon HD 7770 has a GPU core speed of 1000 MHz, and the 1024 MB of GDDR5 memory runs at 1125 MHz through a 128-bit bus. It also is comprised of 640 Stream Processors, 40 Texture Address Units, and 16 ROPs.
Compare those specifications to the Radeon HD 7850, which comes with GPU clock speed of 860 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 is 113% quicker than the Radeon HD 7770 overall, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7850 is much (about 38%) faster with regards to AF than the Radeon HD 7770. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 7770, 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: Bandwidth is the maximum amount of data (counted in MB per second) that can be transported past the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.