Compare any two graphics cards:
Radeon HD 5830 vs Radeon HD 6850
IntroThe Radeon HD 5830 has a clock frequency of 800 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is made up of 1120(224x5) SPUs, 56 TAUs, and 16 ROPs.
Compare those specifications to the Radeon HD 6850, which features a core clock speed of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It is comprised of 960 SPUs, 48 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same memory bandwidth, so in theory they should perform the same. (explain)
Texel RateThe Radeon HD 5830 is a bit (about 20%) better at AF than the Radeon HD 6850. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 6850 is the winner, 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: Memory bandwidth is the maximum amount of information (counted in megabytes per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, the result should 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, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.