Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 6850
IntroThe Radeon HD 5770 has a GPU core clock speed of 850 MHz, and the 1024 MB of GDDR5 memory runs at 1200 MHz through a 128-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare that to the Radeon HD 6850, which uses a 40 nm design. AMD has set the core frequency at 775 MHz. The GDDR5 memory runs at a frequency of 1000 MHz on this specific card. It features 960 SPUs along with 48 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6850 should be 67% faster than the Radeon HD 5770 overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 6850 is a little bit (approximately 9%) better at AF than the Radeon HD 5770. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 6850 is superior to the Radeon HD 5770, 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: Bandwidth is the maximum amount of data (counted in MB per second) that can be transferred over the external memory interface in one second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the 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 are applied per second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better 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 maximum number of pixels the video card can possibly record to its 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 core clock speed. ROPs (Raster Operations Pipelines - also sometimes 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 of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.