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 frequency of 1000 MHz. It also makes use of a 256-bit bus, and makes use of a 40 nm design. It is comprised of 1120(224x5) SPUs, 56 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 6850, which makes use of a 40 nm design. AMD has set the core speed at 775 MHz. The GDDR5 memory runs at a frequency of 1000 MHz on this card. It features 960 SPUs as well as 48 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so theoretically they should perform the same. (explain)
Texel RateThe Radeon HD 5830 is a small bit (about 20%) more effective at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6850 should be quite a bit (more or less 94%) faster with regards to FSAA than the Radeon HD 5830, and also capable of handling higher resolutions better. (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 (counted in MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 applied in one second. This number is worked out by multiplying the total number of texture units of the card by the core clock 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the card's 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 rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.