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 set the core speed at 625 MHz. The GDDR3 RAM works at a speed of 993 MHz on this card. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Compare all that to the Radeon HD 6850, which features a GPU core clock speed of 775 MHz, and 1024 MB of GDDR5 memory running at 1000 MHz through a 256-bit bus. It also is made up of 960 SPUs, 48 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6850 should be 101% quicker than the Radeon HD 4850 512MB in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 6850 will be much (more or less 49%) more effective at anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6850 is superior to the Radeon HD 4850 512MB, 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 data (counted in MB per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.