Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 6850
IntroThe Radeon HD 4850 512MB features a GPU core clock speed of 625 MHz, and the 512 MB of GDDR3 memory runs at 993 MHz through a 256-bit bus. It also features 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.
Compare all of that 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 model. It features 960 SPUs along with 48 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6850 should theoretically be a lot faster than the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 6850 is a lot (about 49%) more effective at AF than the Radeon HD 4850 512MB. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 6850 is the winner, by far. (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 information (in units of MB per second) that can be moved over the external memory interface in one second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed 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 this number, the better the video card will be at 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 that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.