Compare any two graphics cards:
Radeon HD 5830 vs Radeon HD 6850
IntroThe Radeon HD 5830 uses a 40 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 memory works at a frequency of 1000 MHz on this model. It features 1120(224x5) SPUs along with 56 Texture Address Units and 16 Rasterization Operator Units.
Compare that to the Radeon HD 6850, which comes with core clock speeds of 775 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 RAM. 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 have the same performance. (explain)
Texel RateThe Radeon HD 5830 is a little bit (more or less 20%) more effective at texture filtering than the Radeon HD 6850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6850 is a better choice, 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 max amount of information (counted in MB per second) that can be transported across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.