Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 6850
IntroThe Radeon HD 4850 512MB uses a 55 nm design. AMD has clocked the core speed at 625 MHz. The GDDR3 memory works at a speed of 993 MHz on this specific card. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Compare all of that to the Radeon HD 6850, which has a core clock frequency of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 256-bit bus, and uses a 40 nm design. It features 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6850 should be a lot faster than the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 6850 is much (approximately 49%) faster with regards to texture filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateThe Radeon HD 6850 is much (more or less 148%) more effective at full screen anti-aliasing than the Radeon HD 4850 512MB, and also capable of handling higher screen resolutions better. (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 (counted in megabytes per second) that can be transferred across the external memory interface in a second. It's calculated by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per 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 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 most pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.