Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6950 2GB
IntroThe Radeon HD 6850 has a core clock speed of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It features 960 SPUs, 48 Texture Address Units, and 32 ROPs.
Compare all of that to the Radeon HD 6950 2GB, which has a GPU core clock speed of 800 MHz, and 2048 MB of GDDR5 RAM running at 1250 MHz through a 256-bit bus. It also is comprised of 1408 SPUs, 88 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 2GB is 25% quicker than the Radeon HD 6850 overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 6950 2GB is a lot (more or less 89%) more effective at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6950 2GB is the winner, though not 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: Memory bandwidth is the max amount of information (counted in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range 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 calculated 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core 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 many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.