Compare any two graphics cards:
Radeon HD 5830 vs Radeon HD 6850
IntroThe Radeon HD 5830 has core speeds of 800 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 1120(224x5) SPUs along with 56 Texture Address Units and 16 ROPs.
Compare all that to the Radeon HD 6850, which makes use of a 40 nm design. AMD has set the core frequency at 775 MHz. The GDDR5 RAM works at a frequency of 1000 MHz on this card. It features 960 SPUs as well as 48 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same memory bandwidth, so in theory they should have the same performance. (explain)
Texel RateThe Radeon HD 5830 is just a bit (approximately 20%) better at texture filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6850 is much (approximately 94%) more effective at full screen anti-aliasing than the Radeon HD 5830, and able to handle higher resolutions more effectively. (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 largest amount of information (in units of megabytes per second) that can be moved over 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 once again. If 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 high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total texture units 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.