Compare any two graphics cards:
Radeon HD 5830 vs Radeon HD 6850
IntroThe Radeon HD 5830 features clock speeds of 800 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 1120(224x5) SPUs as well as 56 Texture Address Units and 16 Rasterization Operator Units.
Compare that to the Radeon HD 6850, which has a core clock speed of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also makes use of a 256-bit bus, and uses a 40 nm design. It is comprised of 960 SPUs, 48 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact 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 AF than the Radeon HD 6850. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 6850 is superior to the Radeon HD 5830, 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 (measured in MB per second) that can be transported across the external memory interface in one second. It is worked out by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 amount of texture map elements (texels) that can be 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 processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends 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.