Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 6850
IntroThe Radeon HD 4850 512MB makes use of a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR3 memory runs at a frequency of 993 MHz on this particular card. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.
Compare those specs to the Radeon HD 6850, which comes with GPU core speed of 775 MHz, and 1024 MB of GDDR5 memory running at 1000 MHz through a 256-bit bus. It also features 960 Stream Processors, 48 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 6850 should theoretically be much superior to the Radeon HD 4850 512MB overall. (explain)
Texel RateThe Radeon HD 6850 will be a lot (about 49%) better at AF than the Radeon HD 4850 512MB. (explain)
Pixel RateThe Radeon HD 6850 will be a lot (more or less 148%) better at full screen anti-aliasing than the Radeon HD 4850 512MB, and also will be capable of handling higher 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 data (counted in megabytes per second) that can be transferred past the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 applied in one second. This figure is worked out by multiplying the total number of texture units by the core 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. 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 get to the max fill rate.