Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 7770
IntroThe Radeon HD 6850 comes with a GPU core clock speed of 775 MHz, and the 1024 MB of GDDR5 memory runs at 1000 MHz through a 256-bit bus. It also is made up of 960 Stream Processors, 48 TAUs, and 32 Raster Operation Units.
Compare those specifications to the Radeon HD 7770, which has core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6850 should be much faster than the Radeon HD 7770 in general. (explain)
Texel RateThe Radeon HD 7770 is just a bit (approximately 8%) faster with regards to texture filtering than the Radeon HD 6850. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 6850 is superior to the Radeon HD 7770, 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: Bandwidth is the largest amount of data (measured in megabytes per second) that can be moved over the external memory interface in a second. It's worked out by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, 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 number of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount 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 applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.