Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 6850
IntroThe Radeon HD 4850 512MB features a clock frequency of 625 MHz and a GDDR3 memory speed of 993 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare those specifications 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 SPUs, 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 quite a bit superior to the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 6850 should be quite a bit (about 49%) more effective at AF than the Radeon HD 4850 512MB. (explain)
Pixel RateThe Radeon HD 6850 will be much (more or less 148%) faster with regards to full screen anti-aliasing than the Radeon HD 4850 512MB, and also will be capable of handling higher resolutions more effectively. (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 largest amount of information (counted in megabytes per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.