Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6950 2GB
IntroThe Radeon HD 6850 features a GPU core speed of 775 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1000 MHz through a 256-bit bus. It also features 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 6950 2GB, which uses a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 RAM is set to run at a frequency of 1250 MHz on this particular card. It features 1408 SPUs as well as 88 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 2GB should perform much faster than the Radeon HD 6850 overall. (explain)
Texel RateThe Radeon HD 6950 2GB should be a lot (approximately 89%) faster with regards to anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6950 2GB will be just a bit (about 3%) more effective at FSAA than the Radeon HD 6850, and also able to handle 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 largest amount of data (measured in megabytes per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, 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 is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling 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 a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.