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 runs at a speed of 1000 MHz on this particular card. It features 1120(224x5) SPUs along with 56 TAUs and 16 Rasterization Operator Units.
Compare those specs to the Radeon HD 6850, which features a core clock frequency of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is comprised of 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same memory bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe Radeon HD 5830 should be a bit (more or less 20%) more effective at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6850 is superior to the Radeon HD 5830, 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: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be moved past the external memory interface in a second. It is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, 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 calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.